Why Does the Numerator Have to Change?

​Why Does the Numerator Have to Change?

By Susan Peterson

Fractions: Equality - Equivalent Fractions | Number Line | Improper Fraction - PhET Interactive Simulations My Account

You can open this webpage in a new tab.

Copy link

Open in new tab

Open Ended

Build 1/2 using shapes in the simulation.
Then change the denominator to 4 without changing the numerator.

What do you notice about the shaded amount?

Multiple Choice

When you change the denominator, what happens to the size of the pieces?

• The pieces get bigger.

• The pieces get smaller.

• The pieces stay the same.

• The fraction does not change.

Multiple Choice

If the pieces get smaller, what must you do to show the same total amount?

• Shade fewer pieces.

• Shade more pieces.

• Keep the numerator the same.

• Change only the denominator.

Open Ended

Complete the equivalent fraction:

1/2 = ___ / 4

Open Ended

Explain why the numerator must change when the denominator changes.

Multiple Choice

True or False:
If you only change the denominator, the fraction stays equivalent.

• True

• False