NG 2007-06-26

How to keep the image seen while allowing the user to control which part of the text is viewable (scroll).

Instructions

[ Note to developer: Equipment 17 goes in here rather than a test image. ]

It is rather intuitive that 3/4 is greater than 2/4, but it can be very confusing that 1/5 is greater than 1/6. This lab will assist in visualizing that reality.

This lab uses a pair of Circle/Fraction/Decimal graphics to display two unit fractions at the same time. They show the fraction and a corresponding slice of a circle for each of the two fractions. Along with the pie slices the decimal equivalent of each is also displayed. This provides an additional form of feedback to the visual presentation.

A fraction that has a 1 for the numerator we call a unit fraction such as 1/2, 1/7, 1/3. In this lab we will see how we can determine which of two unit fractions is the largest.

A Whole

  1. Notice that there are two light yellow boxes with radio button controls.
  2. In the right box press the 1 on the bottom, this selects the denominator for the right fraction.
  3. In the right box press the 1 on the top, this selects the numerator for the right fraction.
  4. This creates a whole pie.
1/2 of the Whole
  1. In the left box press the 2 on the bottom, this selects the denominator for the left fraction.
  2. In the left box press the 1 on the top, this selects the numerator for the left fraction.
  3. Note that this creates a pie slice that is 1/2 (one half) the size of the original whole pie.
1/4 of the Whole
  1. In the right box press the 4 on the bottom, this selects the denominator for the right fraction.
  2. This creates a pie slice that is 1/4 (one forth) the size of the original whole pie.
Compare Decimal Values for 1/2 to 1/4

Which is larger 1/2 or 1/4?

  1. Look at the decimal value for 1/2. It is .5
  2. Now, look at the decimal value for 1/4. It is .25.
  3. See that .5 is greater than .25. This means that 1/2 is larger than 1/4.
Compare Pie Slices for 1/2 to 1/4
  1. Look at the size of the pie slice for 1/2.
  2. Now, look at the size of the pie slice for 1/4.
  3. Which is bigger?
  4. We can see that the slice for 1/2 is bigger than the slice for 1/4. This means that 1/2 is larger than 1/4.

More

This should be repeated for various unit fractions. The student should predict which will be larger, then use the math lab equipment to verify their prediction.

Modified 26-Jun-2007