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Year 6 Maths — Adding and subtracting decimals

Add and subtract numbers with tenths and hundredths by keeping the columns lined up.

Name: ________________________

Before you start

This line runs from 0 to 1. The numbered ticks are tenths, and the plain ticks between them fall halfway again. Look at how far apart 0.05 and 0.5 really are.

0.000.100.200.300.400.500.600.700.800.901.00

Ten hundredths make one tenth. That is why 0.5 is far bigger than 0.05, even though both are written with a 5.

  1. 1.6 - 0.4 = ?

  2. 2.5.8 - 2.3 = ?

  3. 3.Work each one out, then sort it by how the answer compares with 1.

    Groups: Less than 1 · More than 1

    • 0.6 + 0.7
    • 0.4 + 0.3
    • 0.35 + 0.4
    • 0.9 + 0.2
    • 0.25 + 0.5
    • 0.8 + 0.45

  4. 4.0.75 + 0.25 = ?

  5. 5.7.2 - 3.45 = ?

  6. 6.Tap where 2.6 + 0.7 lands.

    Mark the line with an X.

    2.02.53.03.54.0

  7. 7.A notebook costs $12.50 and a pencil costs $4.25. What do they cost together? Give just the number.

  8. 8.Match each subtraction to its answer.

    • 1 - 0.4
    • 1 - 0.25
    • 1 - 0.05
    • 1 - 0.9
    • 1 - 0.5
    • 0.1
    • 0.5
    • 0.95
    • 0.75
    • 0.6

Answer key — Year 6 Maths — Adding and subtracting decimals

  1. 1. 5.6
  2. 2. 3.5
  3. 3. 0.4 + 0.3 → Less than 1; 0.6 + 0.7 → More than 1; 0.25 + 0.5 → Less than 1; 0.9 + 0.2 → More than 1; 0.35 + 0.4 → Less than 1; 0.8 + 0.45 → More than 1
  4. 4. 1
  5. 5. 3.75
  6. 6. 3.3
  7. 7. 16.75
  8. 8. 1 - 0.4 → 0.6; 1 - 0.25 → 0.75; 1 - 0.05 → 0.95; 1 - 0.9 → 0.1; 1 - 0.5 → 0.5