In calculations involving several operations, the word BEDMAS shows the order in which each operation should be carried out.
BEDMAS
BEDMAS means:
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Brackets:
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Work out the value of any expressions inside brackets.
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Exponents:
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Work out the value of any numbers or expressions with exponents or indices.
Sometimes shown as 'of ' meaning multiply.
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Division
Multiplication
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If these two operations occur together, work from left to right.
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Addition
Subtraction
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If these two operations occur together, work from left to right.
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| Examples |
Answers |
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Calculate:
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a. 3 + 4 × 5
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a. 3 + 4 × 5 = 3 + 20 = 23
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b. 4 + (6 − 2)
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b. 4 + (6 − 2) = 4 + 4 = 8
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c. 13 − 2 × 5 + 4
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c. 13 − 2 × 5 + 4 = 13 − 10 + 4 = 7
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d. 3 × 6 2
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d. 3 × 6 2 = 3 × 36 = 108
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Care should be taken when using a calculator to do calculations of this type.
 Integers
Integers are positive and negative whole numbers and include zero.
Use a number line when adding and subtracting integers.
The first integer is the starting point on the number line.
Addition
- When adding a positive integer, move to the right.
e.g. 4 + 2 = 6
- When adding a negative integer, move to the left.
e.g. 4 + − 2 = 2
Subtraction
- When subtracting a positive integer, move to the left.
e.g. 4 − 2 = 2
- When subtracting a negative integer, move to the right
e.g. 4 − − 2 = 6
Multiplication and division
The rule is the same for both multiplying and dividing two integers.
- If the signs of the two integers are the same, the answer is positive.
- If the signs of the two integers are different, the answer is negative.
The table illustrates these rules:
| ×/÷ |
+ve |
-ve |
| +ve |
+ |
− |
| -ve |
− |
+ |
Examples:
| For multiplication |
For division |
| 4 × 2 = 8 |
4 ÷ 2 = 2 |
| - 4 × − 2 = 8 |
- 4 ÷ − 2 = 2 |
| 4 × − 2 = − 8 |
4 ÷ − 2 = − 2 |
| - 4 × 2 = − 8 |
- 4 ÷ 2 = − 2 |
For practice with integer calculations − 
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