Multiply by the ones and the tens

1 · Learn

For 246 × 23, split 23 into 20 and 3. The partial products are 4,920 and 738. Their total is 5,658.

In the formal layout, the row for 20 must show tens, not just 2. A zero placeholder in the ones column helps record that value. The same method extends to four-digit numbers.

Choose a mental method when the numbers make it helpful. Knowing 6 times 7 is 42 tells us 60 times 7 is 420: each of the six tens is multiplied by seven. Reversing that fact gives 420 divided by 7 = 60. For 25 times 8, double 25 three times: 50, 100, 200.

2 · Worked example

I estimate 250 × 20 = 5,000 and expect a somewhat larger result because the multiplier is 23. I still check each exact partial product.

3 · Your turn

Calculate 1,234 × 24 by splitting 24 into 20 and 4.

4 · Apply your learning

Record the expanded partial products beside a formal long-multiplication layout and explain the place value of every row.