One-digit multiplier
326 x 4 means four groups of 326.
Work from the ones place across.
Year 5
Multiply numbers up to 4 digits by a one- or two-digit number using a formal written method, including long multiplication for two-digit numbers
Use formal written multiplication methods accurately, including long multiplication for two-digit multipliers.
Lesson overview
Number - multiplication and division
Written multiplication keeps each place organised. We multiply one row at a time, then combine the rows carefully. For a two-digit multiplier, the second row stands for tens, not ones.
Two-digit multiplier
124 x 23 means 124 x 20 and 124 x 3.
Split the multiplier into tens and ones.
Combine the rows
Add the partial products to find the total.
Each row must be in the correct place.
Worked example
Calculate 124 x 23.
- Multiply 124 by 3 to get 372.
- Multiply 124 by 20 to get 2,480.
- Add the two partial products.
- The total is 2,852.
Round 1: Learn it
Keep each row in the correct place and combine the partial products carefully.
Finish this round to unlock Round 2: Show you know it.
Question 1
Calculate 326 x 4.
Question 2
Which is 124 x 20?
Question 3
Calculate 124 x 23.
Question 4
What is 403 x 6?
Question 5
Which answer matches 215 x 14?
Common mistakes
Watch for these as you work through the lesson.
- Forgetting that the second row is tens, not ones.
- Misaligning the partial products.
- Adding the rows incorrectly at the end.
Related topics
These ideas connect closely to this lesson.
- Multiply and divide numbers mentally, drawing upon known facts.
- Divide numbers up to 4 digits by a one-digit number using the formal written method of short division and interpret remainders appropriately.