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5th grade math · Unit 2: Adding and subtracting decimals, and money

Subtracting decimals with regrouping

What this lesson shows

5.2 − 3.8 with place value disks: trade 1 one for 10 tenths.

The worked example

The lesson works this one step by step: 5.2 − 3.8. Then your kid tries one like it on paper.

The steps

  1. Not enough tenths
  2. Trade 1 one for 10 tenths
  3. Take away

Helping at home

Start with the smallest place. When there are not enough to take away, trade 1 from the next bigger place for 10 of this one; the number stays the same.

If your kid gets stuck

Is there enough in each place to take away?

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 5.NBT.B.7
    Add, subtract, multiply, and divide decimals to hundredths, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used.
Matches a standard in all 50 states and DCSee each state's code

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