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Grade 7 · Math · Unit 3 of 12

Decimal Operations

Add, subtract, multiply, divide decimals

What your child practises

All four operations with decimals, estimating to check answers, ordering decimals, and money problems such as unit prices.

BC Curriculum learning standard: Operations with decimals: addition, subtraction, multiplication, division and order of operations

How we explain it

Children can open this short lesson before they practise.

  1. To add or subtract, line up the decimal points.
  2. Fill empty places with zeros so the numbers match.
  3. Then add or subtract like whole numbers.

Example: 3.45 + 2.8 = ? Write 2.8 as 2.80 and line up the points. 3.45 + 2.80 = 6.25. Answer: 6.25

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    Which is the best estimate for 59.8 × 9.2?

    • 54
    • 5400
    • 69
    • 540
    Show answer

    540

    Hint: Round each number to a friendly one: 59.8 ≈ 60 and 9.2 ≈ 9. Then 60 × 9 = 540.

  2. Question 2

    What is 4 ÷ 0.5?

    4 ÷ 0.5 = ?

    answer box

    Show answer

    8

    Hint: Multiply both numbers by 10 so you divide by a whole number: 40 ÷ 5 = 8.

  3. Question 3

    What is 6.8 × 0.9?

    6.8 × 0.9 = ?

    • 61.2
    • 0.0612
    • 0.612
    • 6.12
    Show answer

    6.12

    Hint: Multiply as if there were no decimal points: 68 × 9 = 612. The factors have 2 decimal places in total, so the product does too: 6.12.

  4. Question 4

    What is 23.27 + 8.2?

    23.27 + 8.2 = ?

    answer box

    Show answer

    31.47

    Hint: Line up the decimal points and give every number two decimal places: 23.27 + 8.20. Add column by column: 31.47.

  5. Question 5

    Use the order of operations: what is 2.9 + 2.5 × 3?

    2.9 + 2.5 × 3

    • 16.2
    • 11.2
    • 10.5
    • 10.4
    Show answer

    10.4

    Hint: Multiply before adding: 2.5 × 3 = 7.5. Then 2.9 + 7.5 = 10.4.

  6. Question 6

    Put these decimals in order from least to greatest.

    • 0.04
    • 0.094
    • 0.94
    • 0.492
    • 0.49
    Show answer

    0.04 → 0.094 → 0.49 → 0.492 → 0.94

    Hint: Compare tenths first, then hundredths, then thousandths. Writing them with the same number of places helps: 0.040, 0.094, 0.490, 0.492, 0.940.

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