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2nd grade math · Unit 9: Shapes and perimeter

Perimeter by adding sides

What this lesson shows

A garden triangle has sides of 5, 7, and 8 feet. 5 + 7 + 8 = 20 feet of fence, in any order.

The worked example

The lesson works this one step by step: sides of 5, 7, 8 feet. Then your kid tries one like it on paper.

The steps

  1. Perimeter: all the way around
  2. Add every side
  3. Any order
  4. Write the unit

Helping at home

Add the length of every side, in any order you like. Write the unit after the total.

If your kid gets stuck

Add every side.

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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