edcom-728x90

IXL Ad

Illustrative Math-Media4Math Alignment

 

 

Illustrative Math Alignment: Grade 7 Unit 7

Expressions, Equations, and Inequalities

Lesson 12: Solving Problems about Percent Increase or Decrease

Use the following Media4Math resources with this Illustrative Math lesson.

Thumbnail Image Title Body Curriculum Topic
Math Example--Percents-- Equations with Percents: Example 14 Math Example--Percents--Equations with Percents: Example 14 Math Example--Percents--Equations with Percents: Example 14

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "6 is what percent of 2.3?" The solution involves setting up the equation 2.3 * (x / 100) = 6, then solving for x to get x = 6 * (100 / 2.3), which is approximately 260.87%. This example introduces a scenario where the resulting percentage is greater than 100% and involves a decimal base number.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 15 Math Example--Percents--Equations with Percents: Example 15 Math Example--Percents--Equations with Percents: Example 15

Topic

Solving Equations

Description

This math example focuses on solving percent equations by asking "9 is what percent of 38?" The solution involves setting up the equation 38 * (x / 100) = 9, then solving for x to get x = 9 * (100 / 38), which is approximately 23.68%. This example demonstrates how to calculate a percentage when the first number is smaller than the second, resulting in a percentage less than 100%.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 16 Math Example--Percents--Equations with Percents: Example 16 Math Example--Percents--Equations with Percents: Example 16

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "2 is what percent of 55.5?" The solution involves setting up the equation 55.5 * (x / 100) = 2, then solving for x to get x = 2 * (100 / 55.5), which is approximately 3.6036%. This example introduces a scenario where the resulting percentage is a small fraction, less than 5%, and involves a decimal base number.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 17 Math Example--Percents--Equations with Percents: Example 17 Math Example--Percents--Equations with Percents: Example 17

Topic

Solving Equations

Description

This math example focuses on solving percent equations by asking "8 is what percent of 120?" The solution involves setting up the equation 120 * (x / 100) = 8, then solving for x to get x = 8 * (100 / 120), which is approximately 6.67%. This example demonstrates how to calculate a percentage when dealing with larger whole numbers, resulting in a percentage less than 10%.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 18 Math Example--Percents--Equations with Percents: Example 18 Math Example--Percents--Equations with Percents: Example 18

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "3.5 is what percent of 350?" The solution involves setting up the equation 350 * (x / 100) = 3.5, then solving for x to get x = 3.5 * (100 / 350), which equals 1%. This example introduces a scenario where the resulting percentage is a whole number (1%) and involves a decimal number as the first value.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 19 Math Example--Percents--Equations with Percents: Example 19 Math Example--Percents--Equations with Percents: Example 19

Topic

Solving Equations

Description

This math example focuses on solving percent equations by asking "12 is what percent of 8?" The solution involves setting up the equation 8 * (x / 100) = 12, then solving for x to get x = 12 * (100 / 8), which equals 150%. This example demonstrates how to calculate a percentage when the first number is larger than the second, resulting in a percentage greater than 100%.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 2 Math Example--Percents--Equations with Percents: Example 2 Math Example--Percents--Equations with Percents: Example 2

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "What is 7% of 9.5?" The solution involves converting 7% to its decimal equivalent, 0.07, and then multiplying it by 9.5 to obtain the result of 0.665. This example builds upon the previous one by introducing a decimal number as the base value.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 20 Math Example--Percents--Equations with Percents: Example 20 Math Example--Percents--Equations with Percents: Example 20

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "32 is what percent of 1.5?" The solution involves setting up the equation 1.5 * (x / 100) = 32, then solving for x to get x = 32 * (100 / 1.5), which equals 2133.3%. This example introduces a scenario where the resulting percentage is significantly larger than 100% and involves a decimal base number less than 1.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 21 Math Example--Percents--Equations with Percents: Example 21 Math Example--Percents--Equations with Percents: Example 21

Topic

Solving Equations

Description

This math example focuses on solving percent equations by asking "48 is what percent of 55?" The solution involves setting up the equation 55 * (x / 100) = 48, then solving for x to get x = 48 * (100 / 55), which equals 87.27%. This example demonstrates how to calculate a percentage when the two numbers are relatively close in value, resulting in a percentage close to but less than 100%.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 22 Math Example--Percents--Equations with Percents: Example 22 Math Example--Percents--Equations with Percents: Example 22

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "52.2 is what percent of 98.5?" The solution involves setting up the equation 98.5 * (x / 100) = 52.2, then solving for x to get x = 52.2 * (100 / 98.5), which is approximately 52.99%. This example introduces a scenario where both the numerator and denominator are decimal numbers, resulting in a percentage that is also close to the original numerator.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 23 Math Example--Percents--Equations with Percents: Example 23 Math Example--Percents--Equations with Percents: Example 23

Topic

Solving Equations

Description

This math example focuses on solving percent equations by asking "68 is what percent of 320?" The solution involves setting up the equation 320 * (x / 100) = 68, then solving for x to get x = 68 * (100 / 320), which equals 21.25%. This example demonstrates how to calculate a percentage when dealing with whole numbers, resulting in a percentage that's less than 25%.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 24 Math Example--Percents--Equations with Percents: Example 24 Math Example--Percents--Equations with Percents: Example 24

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "75.5 is what percent of 555.25?" The solution involves setting up the equation 555.25 * (x / 100) = 75.5, then solving for x to get x = 75.5 * (100 / 555.25), which is approximately 13.59%. This example introduces a scenario where both the numerator and denominator are decimal numbers, resulting in a percentage that's less than 15%.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 25 Math Example--Percents--Equations with Percents: Example 25 Math Example--Percents--Equations with Percents: Example 25

Topic

Solving Equations

Description

This math example focuses on solving percent equations by asking "125 is what percent of 2?" The solution involves setting up the equation 2 * (x / 100) = 125, then solving for x to get x = 125 * (100 / 2), which equals 6250%. This example demonstrates how to calculate a percentage when the first number is significantly larger than the second, resulting in a percentage well over 100%.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 26 Math Example--Percents--Equations with Percents: Example 26 Math Example--Percents--Equations with Percents: Example 26

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "300 is what percent of 3.5?" The solution involves setting up the equation 3.5 * (x / 100) = 300, then solving for x to get x = 300 * (100 / 3.5), which equals 8571.43%. This example introduces a scenario where the resulting percentage is extremely large, over 8000%, due to the first number being significantly larger than the small decimal base number.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 27 Math Example--Percents--Equations with Percents: Example 27 Math Example--Percents--Equations with Percents: Example 27

Topic

Solving Equations

Description

This math example focuses on solving percent equations by asking "278 is what percent of 99?" The solution involves setting up the equation 99 * (x / 100) = 278, then solving for x to get x = 278 * (100 / 99), which equals 280.80%. This example demonstrates how to calculate a percentage when the first number is significantly larger than the second, resulting in a percentage greater than 200%.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 28 Math Example--Percents--Equations with Percents: Example 28 Math Example--Percents--Equations with Percents: Example 28

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "300 is what percent of 75.5?" The solution involves setting up the equation 75.5 * (x / 100) = 300, then solving for x to get x = 300 * (100 / 75.5), which equals 397.35%. This example introduces a scenario where the resulting percentage is close to 400%, with the first number being significantly larger than the decimal base number.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 29 Math Example--Percents--Equations with Percents: Example 29 Math Example--Percents--Equations with Percents: Example 29

Topic

Solving Equations

Description

This math example focuses on solving percent equations by asking "400 is what percent of 220?" The solution involves setting up the equation 220 * (x / 100) = 400, then solving for x to get x = 400 * (100 / 220), which equals 181.81%. This example demonstrates how to calculate a percentage when the first number is nearly double the second, resulting in a percentage between 150% and 200%.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 3 Math Example--Percents--Equations with Percents: Example 3 Math Example--Percents--Equations with Percents: Example 3

Topic

Solving Equations

Description

This math example focuses on solving percent equations, specifically asking "What is 8% of 58?" The solution involves converting 8% to its decimal form, 0.08, and then multiplying it by 58 to arrive at the answer of 4.64. This example introduces a larger whole number as the base value, demonstrating the scalability of the percent-to-decimal conversion method.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 30 Math Example--Percents--Equations with Percents: Example 30 Math Example--Percents--Equations with Percents: Example 30

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "333.5 is what percent of 500.25?" The solution involves setting up the equation 500.25 * (x / 100) = 333.5, then solving for x to get x = 333.5 * (100 / 500.25), which is approximately 66.67%. This example introduces a scenario where both numbers are decimals and the resulting percentage is less than 100%, showing how to handle more complex decimal calculations.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 31 Math Example--Percents--Equations with Percents: Example 31 Math Example--Percents--Equations with Percents: Example 31

Topic

Solving Equations

Description

This math example focuses on solving percent equations by asking "4 is 0.1% of what number?" The solution involves setting up the equation 4 = 0.001 * x, then solving for x to get x = 4 / 0.001, which equals 4000. This example demonstrates how to calculate the whole when given a very small percentage of it, resulting in a much larger number.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 32 Math Example--Percents--Equations with Percents: Example 32 Math Example--Percents--Equations with Percents: Example 32

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "7 is 1% of what number?" The solution involves setting up the equation 7 = 0.01 * x, then solving for x to get x = 7 / 0.01, which equals 700. This example introduces a scenario where we need to find the whole when given a small percentage of it, resulting in a number 100 times larger than the given value.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 33 Math Example--Percents--Equations with Percents: Example 33 Math Example--Percents--Equations with Percents: Example 33

Topic

Solving Equations

Description

This math example focuses on solving percent equations by asking "9 is 30% of what number?" The solution involves setting up the equation 9 = 0.3 * x, then solving for x to get x = 9 / 0.3, which equals 30. This example demonstrates how to calculate the whole when given a larger percentage of it, resulting in a number that is only slightly larger than the given value.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 34 Math Example--Percents--Equations with Percents: Example 34 Math Example--Percents--Equations with Percents: Example 34

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "1 is 400% of what number?" The solution involves setting up the equation 1 = 4.0 * x, then solving for x to get x = 1 / 4, which equals 0.25. This example introduces a scenario where we need to find a number that, when increased by 400%, results in 1, leading to a fraction or decimal less than 1.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 35 Math Example--Percents--Equations with Percents: Example 35 Math Example--Percents--Equations with Percents: Example 35

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "15 is 0.25% of what number?" The solution involves setting up the equation 15 = 0.0025 * x, then solving for x to get x = 15 / 0.0025, which equals 6000. This example introduces a scenario where we need to find the whole when given a very small percentage of it, resulting in a number that is significantly larger than the given value.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 36 Math Example--Percents--Equations with Percents: Example 36 Math Example--Percents--Equations with Percents: Example 36

Topic

Solving Equations

Description

This math example focuses on solving percent equations by asking "30 is 5% of what number?" The solution involves setting up the equation 30 = 0.05 * x, then solving for x to get x = 30 / 0.05, which equals 600. This example demonstrates how to calculate the whole when given a small percentage of it, resulting in a much larger number.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 37 Math Example--Percents--Equations with Percents: Example 37 Math Example--Percents--Equations with Percents: Example 37

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "50 is 80% of what number?" The solution involves setting up the equation 50 = 0.8 * x, then solving for x to get x = 50 / 0.8, which equals 62.5. This example introduces a scenario where we need to find the whole when given a large percentage of it, resulting in a number that is only slightly larger than the given value.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 38 Math Example--Percents--Equations with Percents: Example 38 Math Example--Percents--Equations with Percents: Example 38

Topic

Solving Equations

Description

This math example focuses on solving percent equations by asking "78 is 150% of what number?" The solution involves setting up the equation 78 = 1.5 * x, then solving for x to get x = 78 / 1.5, which equals 52. This example demonstrates how to calculate the original value when given a percentage greater than 100%, resulting in a number that is smaller than the given value.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 39 Math Example--Percents--Equations with Percents: Example 39 Math Example--Percents--Equations with Percents: Example 39

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "150 is 0.2% of what number?" The solution involves setting up the equation 150 = 0.002 * x, then solving for x to get x = 150 / 0.002, which equals 75,000. This example introduces a scenario where we need to find the whole when given a very small percentage of it, resulting in a number that is significantly larger than the given value.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 4 Math Example--Percents--Equations with Percents: Example 4 Math Example--Percents--Equations with Percents: Example 4

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "What is 6.5% of 45.5?" The solution involves converting 6.5% to its decimal equivalent, 0.065, and then multiplying it by 45.5 to obtain the result of 2.9575. This example introduces both a decimal percentage and a decimal base number, adding complexity to the calculation.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 40 Math Example--Percents--Equations with Percents: Example 40 Math Example--Percents--Equations with Percents: Example 40

Topic

Solving Equations

Description

This math example focuses on solving percent equations by asking "225 is 3% of what number?" The solution involves setting up the equation 225 = 0.03 * x, then solving for x to get x = 225 / 0.03, which equals 7,500. This example demonstrates how to calculate the whole when given a small percentage of it, resulting in a number that is significantly larger than the given value.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 41 Math Example--Percents--Equations with Percents: Example 41 Math Example--Percents--Equations with Percents: Example 41

Topic

Solving Equations

Description

This math example focuses on solving percent equations by asking "400 is 40% of what number?" The solution involves setting up the equation 400 = 0.4 * x, then solving for x to get x = 400 / 0.4, which equals 1000. This example demonstrates how to calculate the whole when given a significant percentage of it, resulting in a number that is larger than the given value.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 42 Math Example--Percents--Equations with Percents: Example 42 Math Example--Percents--Equations with Percents: Example 42

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "650 is 130% of what number?" The solution involves setting up the equation 650 = 1.3 * x, then solving for x to get x = 650 / 1.3, which equals 500. This example introduces a scenario where we need to find the original value when given a percentage greater than 100%, resulting in a number that is smaller than the given value.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 5 Math Example--Percents--Equations with Percents: Example 5 Math Example--Percents--Equations with Percents: Example 5

Topic

Solving Equations

Description

This math example focuses on solving percent equations, specifically asking "What is 30% of 9?" The solution involves converting 30% to its decimal form, 0.3, and then multiplying it by 9 to get the result of 2.7. This example introduces a larger percentage, demonstrating how the method applies consistently across various percentage values.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 6 Math Example--Percents--Equations with Percents: Example 6 Math Example--Percents--Equations with Percents: Example 6

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "What is 28% of 7.2?" The solution involves converting 28% to its decimal equivalent, 0.28, and then multiplying it by 7.2 to obtain the result of 2.016. This example combines a whole number percentage with a decimal base number, further illustrating the versatility of the percent-to-decimal conversion method.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 7 Math Example--Percents--Equations with Percents: Example 7 Math Example--Percents--Equations with Percents: Example 7

Topic

Solving Equations

Description

This math example focuses on solving percent equations, specifically asking "What is 45% of 68?" The solution involves converting 45% to its decimal form, 0.45, and then multiplying it by 68 to arrive at the answer of 30.6. This example introduces a larger percentage and a larger whole number as the base value, demonstrating the scalability of the percent-to-decimal conversion method.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 8 Math Example--Percents--Equations with Percents: Example 8 Math Example--Percents--Equations with Percents: Example 8

Topic

Solving Equations

Description

This math example demonstrates solving percent equations by asking "What is 52.3% of 36.9?" The solution involves converting 52.3% to its decimal equivalent, 0.523, and then multiplying it by 36.9 to obtain the result of 19.2987. This example introduces both a decimal percentage and a decimal base number, adding complexity to the calculation and showcasing the versatility of the percent-to-decimal conversion method.

Solving Percent Equations
Math Example--Percents-- Equations with Percents: Example 9 Math Example--Percents--Equations with Percents: Example 9 Math Example--Percents--Equations with Percents: Example 9

Topic

Solving Equations

Description

This math example focuses on solving percent equations, specifically asking "What is 150% of 8?" The solution involves converting 150% to its decimal form, 1.5, and then multiplying it by 8 to get the result of 12. This example introduces a percentage greater than 100%, demonstrating how the method applies consistently even when dealing with percentages that represent values larger than the whole.

Solving Percent Equations
Math Example--Percents-- Percent Change--Example 1 Math Example--Percents--Percent Change--Example 1 Math Example--Percents--Percent Change--Example 1

This is part of a collection of math examples that focus on percents.

Percents
Math Example--Percents-- Percent Change--Example 10 Math Example--Percents--Percent Change--Example 10 Math Example--Percents--Percent Change--Example 10

This is part of a collection of math examples that focus on percents.

Percents
Math Example--Percents-- Percent Change--Example 2 Math Example--Percents--Percent Change--Example 2 Math Example--Percents--Percent Change--Example 2

This is part of a collection of math examples that focus on percents.

Percents
Math Example--Percents-- Percent Change--Example 3 Math Example--Percents--Percent Change--Example 3 Math Example--Percents--Percent Change--Example 3

This is part of a collection of math examples that focus on percents.

Percents
Math Example--Percents-- Percent Change--Example 4 Math Example--Percents--Percent Change--Example 4 Math Example--Percents--Percent Change--Example 4

This is part of a collection of math examples that focus on percents.

Percents
Math Example--Percents-- Percent Change--Example 5 Math Example--Percents--Percent Change--Example 5 Math Example--Percents--Percent Change--Example 5

This is part of a collection of math examples that focus on percents.

Percents
Math Example--Percents-- Percent Change--Example 6 Math Example--Percents--Percent Change--Example 6 Math Example--Percents--Percent Change--Example 6

This is part of a collection of math examples that focus on percents.

Percents
Math Example--Percents-- Percent Change--Example 7 Math Example--Percents--Percent Change--Example 7 Math Example--Percents--Percent Change--Example 7

This is part of a collection of math examples that focus on percents.

Percents
Math Example--Percents-- Percent Change--Example 8 Math Example--Percents--Percent Change--Example 8 Math Example--Percents--Percent Change--Example 8

This is part of a collection of math examples that focus on percents.

Percents
Math Example--Percents-- Percent Change--Example 9 Math Example--Percents--Percent Change--Example 9 Math Example--Percents--Percent Change--Example 9

This is part of a collection of math examples that focus on percents.

Percents
Math Example--Ratios, Proportions, and Percents--Solving Proportions: Example 1 Math Example--Ratios, Proportions, and Percents--Solving Proportions: Example 1 Math Example--Ratios, Proportions, and Percents--Solving Proportions: Example 1

Topic

Ratios, Proportions, and Percents

Description

This example demonstrates how to solve a proportion problem where two ratios a:b and c:d are proportional. Given the values b = 3, c = 4, and d = 6, we need to find the value of a. The proportion is set up as a / 3 = 4 / 6, which is then solved to find that a = 2.

Proportions
Math Example--Ratios, Proportions, and Percents--Solving Proportions: Example 10 Math Example--Ratios, Proportions, and Percents--Solving Proportions: Example 10 Math Example--Ratios, Proportions, and Percents--Solving Proportions: Example 10

Topic

Ratios, Proportions, and Percents

Description

This example illustrates solving a proportion problem using similar triangles with algebraic expressions. Two triangles are shown, one with sides of 6 and 9, and the other with sides of 2x and 2x + 9. The problem requires setting up a proportion: 6 / 9 = 2x / (2x + 9). Solving this equation leads to x = 9, which then allows us to find the side lengths of 18 and 27.

Proportions
Math Example--Ratios, Proportions, and Percents--Solving Proportions: Example 11 Math Example--Ratios, Proportions, and Percents--Solving Proportions: Example 11 Math Example--Ratios, Proportions, and Percents--Solving Proportions: Example 11

Topic

Ratios, Proportions, and Percents

Description

This example demonstrates solving a proportion problem using similar right triangles. Two right triangles are shown, one with legs of 7 and 9, and the other with legs of 14 and x. The problem requires finding the length of side x by setting up a proportion based on the similar triangles: 7 / 9 = 14 / x. Solving this equation leads to x = 18.

Proportions