Multiplication by a 2 Digit Number
Maths: Year 5 & 6 National Curriculum, topic 5.2.1
Multiplying by a 2 Digit Number With the Column Method
You can also use column multiplication when you multiply by a 2 digit number. The process is slightly different than multiplying by a 1 digit number. Let's look at 4,372 × 24 as an example.
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Setting up your columns
- You set up the multiplication by lining up the digits in your numbers using place value.
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Multiply 4,372 by 4
- The first step is to treat the calculation as you would when multiplying by a one-digit number.
- Multiply 4,372 by 4.
Then multiply by 20
- Then you look at multiplying the 4,372 by 20.
- Multiplying by 20 may seem quite scary.
- But it's easier than you'd think!
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Add in a 0 in the 'ones'
- In our next row, you put a 0 at the end.
- You put a 0 because you are multiplying by a multiple of 10.
- All the multiples of 10 end in 0.
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Multiply 4,372 by 20
- Start by multiplying 2 'ones' by 2 'tens'
- Put your answer in the second row.
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Multiply 7 'tens' by 2 'tens'
- Next, multiply 7 'tens' by 2 'tens'
- Put your answer in the second row.
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Multiply 3 'hundreds' by 2 'tens'
- Next, multiply 3 'hundreds' by 2 'tens'
- Put your answer in the second row.
- Don't forget to add the 1 that was carried from the 'tens'.
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Multiply 4 'thousands' by 2 'tens'
- Next, multiply 4 'thousands' by 2 'tens'
- Put your answer in the second row.
- You have calculated:
- 4,372 × 4 = 17,488
- 4,372 × 20 = 87,440
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Add to find you answer
- 4,372 × 24 is the same as (4,372 × 4) (4,372 × 20).
- 4,372 × 24 = (4,372 × 4) (4,372 × 20)
- 4,372 × 24 = 17,488 87,440
- 4,372 × 24 = 104,928
Test yourself on Multiplication by a 2 Digit Number
What digit goes in the 'ones' column of the second row?
What calculation do you do next?
What digit goes in the 'ones' column of the second row?
What calculation do you do next?