AP Aussie Primary Academy

Year 1 · Maths · Number · Free Printable

Subtraction Within 20

Help Year 1 students build fluency with subtraction facts within 20 using pictures, numbers and simple word problems.

AC9M1N04MathsNumberAnswer Key Included

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Learning Intention

Students will subtract numbers within 20 using concrete materials, drawings and number facts.

Australian Curriculum

AC9M1N04

Add and subtract numbers within 20, using part-part-whole reasoning and number facts.

Teacher Notes

Use counters or ten-frames. Practise “taking away” and “finding the difference” before written subtraction.

Skills Practised

  • Subtraction within 20
  • Number facts
  • Part-part-whole
  • Problem solving

Subtracting Within 20

Subtraction tells us how many are left or how far apart two numbers are. Children can use counting back, objects, drawings or number facts.

A Reliable Method

  1. Start with the larger number.
  2. Count back the amount being subtracted.
  3. Say the answer and check it.
  4. Use addition to see whether the result makes sense.

For example, if 14 − 5 is 9, check with 9 + 5 = 14.