Use a clear written layout
23 x 4 means 2 tens and 3 ones are each multiplied by 4.
Keep the place values clear before multiplying.
Year 4
Multiply two-digit and three-digit numbers by a one-digit number using formal written layout
Use place value and a clear written layout to multiply two-digit and three-digit numbers by a one-digit number.
Lesson overview
Number - multiplication and division
When multiplying by a one-digit number, it helps to line up the place values clearly. We work through the ones, tens and hundreds carefully, keeping track of the value in each place.
Multiply each place
34 x 3 gives 12 ones and 9 tens, so the total is 102.
Think about what each digit is worth.
Three-digit by one-digit
123 x 4 uses the same structure, just with hundreds as well.
The written layout helps with larger numbers.
Worked example
Work out 132 x 3.
- Multiply the ones: 2 x 3 = 6.
- Multiply the tens: 3 tens x 3 = 9 tens.
- Multiply the hundreds: 1 hundred x 3 = 3 hundreds.
- So the answer is 396.
Round 1: Learn it
Keep the written layout tidy and think about the value in each place.
Finish this round to unlock Round 2: Show you know it.
Question 1
What is 24 x 3?
Question 2
What is 31 x 4?
Question 3
132 x 2 =
Question 4
Which answer is correct for 213 x 3?
Question 5
Why does written layout help with 123 x 4?
Common mistakes
Watch for these as you work through the lesson.
- Treating tens as ones.
- Missing one place value in the calculation.
- Writing the digits of the answer in the wrong order.
Related topics
These ideas connect closely to this lesson.
- Use place value, known and derived facts to multiply and divide mentally.
- Solve problems involving multiplying and adding, including integer scaling problems and harder correspondence problems such as n objects are connected to m objects.