Boba Maths

Year 6 · Arithmetic skills · Skill 5A

Skill 5A: Smile multiplication

Multiply multiples of 10, 100 and 1,000 quickly by counting the zeros.

Download the sheets

Each file is an editable Word document (.docx) with 25 questions in five columns. It opens in Word, Google Docs, Pages and LibreOffice, so you can change questions or add working space before printing.

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Worked examples

Smile multiplication is a quick way to multiply numbers that end in zeros. Multiply the non-zero digits, count all the zeros, then put them back.

Example 1

A tens number times 1,000

60 × 1,000

  1. Look at the zeros on the end of both numbers. They are the clue.
    60 × 1,000
  2. Cover the zeros and multiply the digits that are left: 6 × 1 = 6.
  3. Count every zero you covered. 1 + 3 = 4 zeros altogether. Draw a smile under them so none get lost.
  4. Write 6 and put all 4 zeros back on the end: 60,000.

Answer: 60,000

Example 2

A hundreds number times 100

700 × 100

  1. Look at the zeros on the end of both numbers. They are the clue.
    700 × 100
  2. Cover the zeros and multiply the digits that are left: 7 × 1 = 7.
  3. Count every zero you covered. 2 + 2 = 4 zeros altogether. Draw a smile under them so none get lost.
  4. Write 7 and put all 4 zeros back on the end: 70,000.

Answer: 70,000

Top tips

  • Zeros from both numbers all count.
  • Draw the smile under the zeros so you can count them easily.
  • The answer is the multiplied digits followed by every zero.

Watch out for

  • Counting the zeros in only one of the numbers.
  • Forgetting a zero, or adding too many.

Try some questions

These are from the worksheet. Work each one out, then open it to check.

  1. 20 × 10 =
    Show the answer

    200

  2. 400 × 10 =
    Show the answer

    4,000

  3. 300 × 100 =
    Show the answer

    30,000

  4. 80 × 1000 =
    Show the answer

    80,000

All arithmetic skills

Skill 1ASkill 1BSkill 2ASkill 2BSkill 3ASkill 4ASkill 4BSkill 5BSkill 6ASkill 6BSkill 6CSkill 6DSkill 7ASkill 8ASkill 9ASkill 10ASkill 10BSkill 10CSkill 11ASkill 11BSkill 11CSkill 12ASkill 13ASkill 14A

Arithmetic skills overview · Year 6 overview