Method C - Expanded Form Method

Test yourself

Expanded Form Method: 753 − 491

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

Step 1

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

Step 2

Now set them out in columns.

Step 3

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

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.

Step 5

Now we can subtract 90 from 150.

Step 6

And subtract 400 from 600.

Step 7

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

1Course Overview

1.1Course Structure & Commonly Asked Questions

1.1.1Introduction to the Course & Common Questions

2Subtraction: KS2/3

2.1Subtraction Methods

2.1.1Method A - Decomposition Method

2.1.2Method B - Equal Addition Method

2.1.3Method C - Expanded Form Method

2.1.4Method D - Partitioning Method

2.1.5Method E - Counting-Up Method

2.1.6Method F - Constant Difference Method

2.1.7Method G - Partial Differences Method

2.1.8Method H - Complementary Method

2.1.9Method I - Nines Complement Method

3Expanding Double Brackets: KS3/4

3.1Expansion Methods

3.1.1Method A - Grid Method

3.1.2Method B - Each by Each

3.1.3Method C - Distributive Law

3.1.4Method D - Inspection

3.1.5Method E - Column Method

3.1.6Method F - Vertical & Crosswise

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