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4th grade math · Unit 5: Fractions

Simplest form

What this lesson shows

8/12: 8 and 12 share the factor 4, so 8/12 = 2/3. 2 and 3 share only 1, so 2/3 is in simplest form. Fraction strips show 8/12 and 2/3 are the same length.

The worked example

The lesson works this one step by step: 8/12. Then your kid tries one like it on paper.

The steps

  1. List the factors of each
  2. Divide both by the greatest shared one
  3. Check: they share only 1

Helping at home

Your kid lists the factors of the top and of the bottom, circles the greatest one they share, and divides both by it. Then they check the new top and bottom share only 1. If they divided by a smaller factor, they divide again.

If your kid gets stuck

What is the greatest factor they share?

Watch it with Lux

With Lux, this lesson is a narrated video and a printed page your kid works on. Then Lux helps with the same math on their own worksheet, one question at a time.

See how Lux works

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