Boba Maths

Year 6 · Arithmetic skills · Skill 1A

Skill 1A: Adding 10, 100 and 1,000

Add 10, 100 or 1,000 to numbers up to 5 digits by changing the right digit.

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.

Download the worksheet Download the answers Generate a new sheet for this skill

Worked examples

Adding 10, 100 or 1,000 changes just one digit, as long as you know which column to look at. Children who see this pattern can answer these in their heads.

Example 1

Adding 100

4,386 + 100

  1. We are adding 100, which is 1 hundred. So look at the hundreds column only.
    4,386 in a place value table
    ThHTO
    Start4386
  2. The hundreds digit goes up by 1: 3 + 1 = 4. Every other digit stays exactly the same.
    Before and after
    ThHTO
    Start4386
    Add 1004486
  3. So 4,386 + 100 = 4,486.

Answer: 4,486

Example 2

Adding 10, with a carry

5,792 + 10

  1. We are adding 10, which is 1 ten. So look at the tens column only.
    5,792 in a place value table
    ThHTO
    Start5792
  2. The tens digit is 9. 9 + 1 = 10, which is too big for one column, so write 0 and carry 1 into the hundreds column.
    Before and after
    ThHTO
    Start5792
    Add 105802
  3. So 5,792 + 10 = 5,802.

Answer: 5,802

Example 3

Adding 1,000 to a 5-digit number

38,640 + 1,000

  1. We are adding 1,000, which is 1 thousand. So look at the thousands column only.
    38,640 in a place value table
    TThThHTO
    Start38640
  2. The thousands digit goes up by 1: 8 + 1 = 9. Every other digit stays exactly the same.
    Before and after
    TThThHTO
    Start38640
    Add 1,00039640
  3. So 38,640 + 1,000 = 39,640.

Answer: 39,640

Top tips

  • 10 is one ten, 100 is one hundred and 1,000 is one thousand: add 1 to that column.
  • Say the number aloud in words first (“four thousand, three hundred and eighty-six”) and the hundreds digit is easy to spot.
  • The order does not matter: 1,000 + 245 is the same as 245 + 1,000.

Watch out for

  • Changing the wrong column, for example adding 1 to the tens when adding 100.
  • Forgetting to carry when the digit is 9, such as 5,792 + 10.

Try some questions

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

  1. 76 + 100 =
    Show the answer

    176

  2. 4,821 + 10 =
    Show the answer

    4,831

  3. 8,234 + 100 =
    Show the answer

    8,334

  4. 10 + 89,765 =
    Show the answer

    89,775

All arithmetic skills

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

Arithmetic skills overview · Year 6 overview