Skill: fraction-operations

Fraction Operations Lab

Drag the sliders and watch the bars. For adding and subtracting, hunt for the denominator where the pieces line up. For dividing, ask “how many fit?” Then test yourself with challenges.

Add / subtract explorer

First fraction

Second fraction

Renamed with the common denominator

Division: how many fit?

Use the sliders on the right, then read the answer here.

Controls

First numerator 2

First denominator 3

Second numerator 1

Second denominator 4

Common denominator 12

Drag until the pieces line up

How many fit?

Big fraction numerator 2

Big fraction denominator 3

Small fraction numerator 1

Small fraction denominator 6

Challenges

1. Build 2/3 + 1/4 and find the smallest lining-up denominator

Press “Set 2/3 + 1/4”, then drag the common-denominator slider. At which values do the pieces line up? Why is 12 the smallest?

2. Predict 2/3 ÷ 1/6 with “how many fit?”

How many 1/6 pieces fit inside 2/3? Type your prediction, then check — keep-change-flip should agree.

3. Invent a subtraction that equals exactly 1/2

Use denominators 8 and 6: drag the sliders until a/8 − b/6 = 1/2.

a (over 8) 8

b (over 6) 3