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Everyday maths 1 (Wales)
Everyday maths 1 (Wales)

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4.3 Calculations using decimals

When you make any calculation with decimals – that is, addition, subtraction, multiplication and division – it is very important to make sure that the decimal point is in the correct place. If you don’t, you’ll get the wrong answer.

Case study _unit2.4.4 Adding and subtracting decimals

When we add or subtract decimals, it is important to line up the decimal points.

Calculate the following:

  1. 14.08 + 4.1
  2. 34.45 – 2.3

Method

Described image
Figure _unit2.4.5 Figure 24 Calculating using decimals

Now try the following activity. Remember to check your answers once you have completed the questions.

Activity _unit2.4.5 Activity 27: Using decimals

Now try the following activity using written methods. Remember to check your answers once you have completed the questions.

  1. 4.2 + 3.7
  2. 6.7 – 5.1
  3. 42.19 + 13.5
  4. 74.8 – 24.3
  5. £163.25 + £27.12
  6. 2.1 m – 0.75 m

Answer

  1. 7.9
  2. 1.6
  3. 55.69
  4. 50.5
  5. £190.37
  6. 1.35 m