Activity – (Adding Fractions)

Instructions. In this activity, we are going to add fractions in which the denominators are different.

Step 1: Pull the black slider to the top of the bar and count the shaded sectors of the circle.

Step 2: Check the Least Common Denominator box to see the calculations.

Step 3: Pull the Answer slider below to see the answer.

Step 4: Click on the reset button at the top right to do another problem.

Step 5: Change the red fraction to 1/2 and the blue fraction to 1/6.

Step 6: Pull the black slider again to the top and note the shaded sectors of the circle.

Step 7: Check the Least Common Denominator box to see the calculations.

Step 8: Pull the Answer slider below to see the answer.

Step 9: Repeat the process using the fractions 1/3 and 1/4. Then find answers to the questions below.

When you checked the box in the first problem, why was the numerator and denominator of the first fraction multiplied by 2 ?

When you checked the Lowest Common Denominator box in the second problem, the numerator and denominator of one fraction multiplied by three. Was it to have an equal number of divisions of both circles ?

Can it be concluded from the third problem that one way to add up fractions with different denominators is to multiply both the numerator and denominator by some positive integers to get a common denominator?

1/3 + 1/7 =

2/9 + 7/9 =

1/3 + 1/4 =

3/4 + 2/3 =

5/6 + 2/3 =

Do some more practice.