Steps to Success - Subtraction

Step 1 – Early Learning

Children are taught to understand subtraction as taking away (counting back) and finding the difference (counting up)

Step 2 - Informal Written Methods

Counting on or Counting back?

Method A Counting on If the numbers are close together like 203 – 198 it’s quicker to count on. If they’re a long way apart like 203 – 5 it’s quicker to take away.

Bead strings or bead bars can be used to illustrate subtraction including bridging through ten by counting back 3 then counting back 2.

T0 T0

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Steps to Success - Subtraction

Step 2 - Informal Written Methods Continued

Method B Counting back Sometimes I count back because that’s easier than taking away.

Step 3 – Beginning Formal Written Methods

Expanded method working towards decomposition.

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Subtract the ones, tens then hundreds

Steps to Success - Subtraction

Decomposition

Step 4- Using Formal Written Methods Step 3 – Beginning Formal Written Methods Continued

Expanded method working towards decomposition.

HT0 - T0

HT0 - HT0