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4th grade math · Unit 6: Decimals and money

Fixed and variable expenses

What this lesson shows

Rent is the same every month, a fixed expense; the grocery bill changes, a variable one. Then share a $10 allowance among spending, saving, and giving.

The worked example

The lesson works this one step by step: a $10 allowance: spend $5, give $2. Then your kid tries one like it on paper.

The steps

  1. Fixed: the same every month
  2. Variable: it changes
  3. Spend + save + give = allowance

Helping at home

Read each bill aloud: one that costs the same every month is fixed, one that changes is variable. Then your kid subtracts spending and giving from the allowance to find what is saved, and adds the three parts back to check.

If your kid gets stuck

Same every month: fixed. Changes: variable.

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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