Clock Face Showing 12

Topic

Time Measurement

Description

This image depicts a clock face showing 12 o'clock, a fundamental reference point in time measurement. The clear positioning of the hour and minute hands at the 12 mark illustrates the concept of a new hour, making it a perfect visual aid for teaching time-telling skills.

Teachers can use this image to explain the significance of the 12 o'clock position in both analog and digital time formats. It serves as a starting point for lessons on understanding AM and PM, as well as the transition between hours.

Incorporating math clip art like this into lessons is vital for visual learners, as it provides a concrete representation of abstract time concepts. It aids in developing students' ability to read clocks accurately and confidently.

Teacher's Script: "Let's look at this clock showing 12 o'clock. Notice how both hands point to the 12. This is an important time because it marks the beginning of a new hour. Can you think of what happens at 12 o'clock in your daily routine?"

For a complete collection of math clip art related to Telling Time click on this link: Clock Face Collection.

Video: Telling Time

To review telling time, watch this video. (The transcript is also included.)

The Hour Hand

When you look at a clock, you can read the hour and the minutes. Here is a blank clock face. Look at the arrangement of numbers on the clock face. Make a note of the following items:

• The numbers go from 1 to 12.
• There are additional tic marks between the main numbers.

Let’s start by looking at the hour hand. It is the shorter of the two clock hands and looks like this.

The hour hand varies in value from 1 to 12. Here are some sample times using the hour hand.

The Minute Hand

The minute hand is the longer of the two clock hands. This is what it looks like.

The minute hand varies in value from 0 to 60. Here are some sample times using the minute hand.

Why Are Hours Measured From 1-12 Not 1-10?

We are so accustomed to counting objects from 1-10 and in multiples of 10. Why are minutes and hours different? Why are minutes counted from 1 to 60? Why are hours counted from 1 to 12?

When we count from 1 to 10, we are using the base 10 system. The numbers cycle through groups of 10. But with clocks there is a different number system at work. Can you tell what the base is?

Clocks rely on a base 60 system. Think of the minute hand. After 60 minutes, the clock advances one hour and the minutes start again. This is an example of counting in base 60.

Why 60? With time measurement, we want to keep precise track of the time. The number 60 has many more factors, so we can measure time in fractions of 60 that are numbers that can be easily be remembered. Using base 10 with clocks would result in awkward fractions of time.

This table shows the fractions of an hour that result in whole number minutes of time that are easy to remember.

With base 60, there are so many more fractional amounts of time that are whole numbers, and they're easy to remember. Try this with base 10 and you won't end up with as many, easy-to-remember fractions.