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Home > Maths I > Numbers and Money > Negative whole numbers

Maths I

Negative whole numbers

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Subtracting negative whole numbers

Subtracting a negative number is straightforward if you follow this rule -

a - (-b)

a + b

Example 1

  • 9 - (-1)
  • = 9 + 1
  • = 10

Example 2

  • 6 - (-14)
  • = 6 + 14
  • = 20

Example 3

  • - 5 - (-3)
  • = - 5 + 3
  • = - 2

Example 4

  • - 9 - (-12)
  • = - 9 + 12
  • = 3

Now try these questions:

You don't need to draw the number line if you can manage without it.

Question

4 - (-8)

Answer
  • 4 - (-8)
  • = 4 + 8
  • = 12
Question

9 - (-11)

Answer
  • 9 - (-11)
  • = 9 + 11
  • = 20
Question

-8 - (-3)

Answer
  • - 8 - (-3)
  • = - 8 +3
  • = - 5
Question

- 19 - (-30)

Answer
  • - 19 - (-30)
  • = - 19 + 30
  • = 11

Now try an Activity or go straight to a Test Bite

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