2.1.3

Method C - Expanded Form Method

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Expanded Form Method: 753 − 491

This method is identical to the Decomposition Method (Method A) except we show the decomposition much more clearly.

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Step 1

  • Write out the subtrahend and the minuend as a sum of their hundreds, tens and ones.
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Step 2

  • Now set them out in columns.
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Step 3

  • Start at the right. Subtract 1 from 3.
  • Write the difference at the bottom, in the ones column.
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Step 4

  • Now we want to subtract 90 from 50. To do this without using negatives, we can exchange.
  • Instead of writing 750 as 700 + 50, we write it as 600 + 150.
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Step 5

  • Now we can subtract 90 from 150.
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Step 6

  • And subtract 400 from 600.
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Step 7

  • The difference is the sum of the numbers in the bottom row.
    • 200 + 60 + 2 = 262.

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