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3rd grade math · Unit 5: Fractions

Equal parts only

What this lesson shows

Fixes a mistake

Four parts that are not equal are not fourths.

The worked example

The lesson works this one step by step: 1/4. Then your kid tries one like it on paper.

The steps

  1. Count the parts
  2. Check they are equal
  3. Equal parts fill the whole

Helping at home

Before naming a fraction, check that every part is the same size. If the parts are not equal, the shaded part is not 1 of that many equal parts, so it has no fraction name yet.

If your kid gets stuck

Are all the parts the same size?

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

Standards

  • Common Core 3.NF.A.1
    Understand a fraction 1/b as the quantity formed by 1 part when a whole is partitioned into b equal parts; understand a fraction a/b as the quantity formed by a parts of size 1/b.
  • Common Core 3.G.A.2
    Partition shapes into parts with equal areas. Express the area of each part as a unit fraction of the whole. For example, partition a shape into 4 parts with equal area, and describe the area of each part as 1/4 of the area of the shape.
Matches a standard in all 50 states and DCSee each state's code

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