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Dividing by Medium Numbers

Factor the divisor into smaller numbers and divide step by step.

When to use

Dividing by a 2-digit number (10-99).

Steps

  1. 1.Try to factor the divisor (e.g. 24 = 4 x 6)
  2. 2.Divide by the first factor, then by the second
  3. 3.If the divisor is prime, use long division or estimation

Example: 500,000 / 25

Factor 25 = 5 x 5

500,000 / 5 = 100,000

100,000 / 5 = 20,000

Mental approach

500,000 / 25: think 25 = 5 x 5, so 500,000 / 5 = 100,000 then / 5 = 20,000.

Pen & paper approach

Write the factored division as two separate steps.

Tips

  • •Common factorizations: 12=3x4, 15=3x5, 18=2x9, 24=4x6, 25=5x5, 36=4x9
  • •For /25: multiply by 4 then /100 (since 25 x 4 = 100)
  • •For /50: multiply by 2 then /100

Try it yourself

7,200 / 24

450,000 / 15

1,800 / 36