Source: https://senecalearning.com/en-gb/revision-notes/teacher-cpd/cpd-for-primary-subtraction-methods-for-ks2-maths-seneca-certified/2-1-3-method-c-expanded-form-method

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# Method C - Expanded Form Method

CPD for Primary: Subtraction Methods for KS2 Maths (by Jo Morgan), topic 2.1.3

## 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

![Step 1](https://image-v2.cdn.app.senecalearning.com/2020-04/714cf0bc-be0c-47c3-9186-46b8a0778127/Method%20C%20-%20Example%201%20(1).png)

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

### Step 2

![Step 2](https://image-v2.cdn.app.senecalearning.com/2020-04/c0d548a5-b123-4dc8-bafd-fb3b86313094/Method%20C%20-%20Example%201%20(10).png)

- Now set them out in columns.

### Step 3

![Step 3](https://image-v2.cdn.app.senecalearning.com/2020-04/1a988ce6-176a-4d93-81a2-ef1f668a5bdd/Method%20C%20-%20Example%201%20(11).png)

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

### Step 4

![Step 4](https://image-v2.cdn.app.senecalearning.com/2020-04/5fcda503-d2ab-4db9-90fe-086d14f67410/Method%20C%20-%20Example%201%20(12).png)

- 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

![Step 5](https://image-v2.cdn.app.senecalearning.com/2020-04/3a4e16f3-064a-4a57-9b72-77c4323ed513/Method%20C%20-%20Example%201%20(13).png)

- Now we can subtract 90 from 150.

### Step 6

![Step 6](https://image-v2.cdn.app.senecalearning.com/2020-04/daedd770-1876-4481-b577-dfbd8b54bed9/Method%20C%20-%20Example%201%20(14).png)

- And subtract 400 from 600.

### Step 7

![Step 7](https://image-v2.cdn.app.senecalearning.com/2020-04/c06f59f4-df95-479a-b5f0-acc37fc82f3b/Copy%20of%20Method%20C%20-%20Example%201.png)

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

## Test yourself on Method C - Expanded Form Method

- Which part of this student's working is incorrect?
- Has the student gone wrong? If so, where?

[Practise this topic for free](https://app.senecalearning.com/classroom/course/eab4f483-2118-4224-8daa-b5f64232f209/section/b8e2af49-2d18-4718-875b-4017464ac197/session)

- Previous topic: [2.1.2 Method B - Equal Addition Method](https://senecalearning.com/en-gb/revision-notes/teacher-cpd/cpd-for-primary-subtraction-methods-for-ks2-maths-seneca-certified/2-1-2-method-b-equal-addition-method.md)
- Next topic: [2.1.4 Method D - Partitioning Method](https://senecalearning.com/en-gb/revision-notes/teacher-cpd/cpd-for-primary-subtraction-methods-for-ks2-maths-seneca-certified/2-1-4-method-d-partitioning-method.md)

## CPD for Primary: Subtraction Methods for KS2 Maths (by Jo Morgan) contents

### 1 Course Overview
- 1.1 Course Structure & Commonly Asked Questions
  - [1.1.1 Introduction to the Course & Common Questions](https://senecalearning.com/en-gb/revision-notes/teacher-cpd/cpd-for-primary-subtraction-methods-for-ks2-maths-seneca-certified/1-1-1-introduction-to-the-course-and-common-questions.md)

### 2 Subtraction Methods
- 2.1 Subtraction Methods
  - [2.1.1 Method A - Decomposition Method](https://senecalearning.com/en-gb/revision-notes/teacher-cpd/cpd-for-primary-subtraction-methods-for-ks2-maths-seneca-certified/2-1-1-method-a-decomposition-method.md)
  - [2.1.2 Method B - Equal Addition Method](https://senecalearning.com/en-gb/revision-notes/teacher-cpd/cpd-for-primary-subtraction-methods-for-ks2-maths-seneca-certified/2-1-2-method-b-equal-addition-method.md)
  - [2.1.3 Method C - Expanded Form Method](https://senecalearning.com/en-gb/revision-notes/teacher-cpd/cpd-for-primary-subtraction-methods-for-ks2-maths-seneca-certified/2-1-3-method-c-expanded-form-method.md)
  - [2.1.4 Method D - Partitioning Method](https://senecalearning.com/en-gb/revision-notes/teacher-cpd/cpd-for-primary-subtraction-methods-for-ks2-maths-seneca-certified/2-1-4-method-d-partitioning-method.md)
  - [2.1.5 Method E - Counting-Up Method](https://senecalearning.com/en-gb/revision-notes/teacher-cpd/cpd-for-primary-subtraction-methods-for-ks2-maths-seneca-certified/2-1-5-method-e-counting-up-method.md)
  - [2.1.6 Method F - Constant Difference Method](https://senecalearning.com/en-gb/revision-notes/teacher-cpd/cpd-for-primary-subtraction-methods-for-ks2-maths-seneca-certified/2-1-6-method-f-constant-difference-method.md)
  - [2.1.7 Method G - Partial Differences Method](https://senecalearning.com/en-gb/revision-notes/teacher-cpd/cpd-for-primary-subtraction-methods-for-ks2-maths-seneca-certified/2-1-7-method-g-partial-differences-method.md)
  - [2.1.8 Method H - Complementary Method](https://senecalearning.com/en-gb/revision-notes/teacher-cpd/cpd-for-primary-subtraction-methods-for-ks2-maths-seneca-certified/2-1-8-method-h-complementary-method.md)
  - [2.1.9 Method I - Nines Complement Method](https://senecalearning.com/en-gb/revision-notes/teacher-cpd/cpd-for-primary-subtraction-methods-for-ks2-maths-seneca-certified/2-1-9-method-i-nines-complement-method.md)