Multi-digit multiplication (grade 4) · lesson

Break the big number by place

💡 Multiply each place of the big number, then add the parts.

Split the big number into thousands, hundreds, tens, and ones. Multiply each part by the small number.

Then add all the parts. Each part is easy, and the sum is the answer.

🧠 Let's work it out

Find 63 × 4.

What do you think comes next?

💡 To multiply by a number like 40, multiply by 4 and then by 10.

40 is 4 × 10. So multiply by 4 first.

Then times by 10. That puts a 0 on the end of a whole number.

🧠 Let's work it out

Find 28 × 40.

What do you think comes next?

💡 Split one two-digit number into tens and ones, multiply each part, then add.

Pick one number and split it into tens and ones. 14 is 10 + 4.

Multiply the other number by each part. Then add the two products. Story problems with packs or rows work the same way.

🧠 Let's work it out

Find 27 × 14.

What do you think comes next?