Multiply by two digits
- Age
- Ages 9–10
For 23 × 14, calculate 23 × 4 = 92 and 23 × 10 = 230. Add the partial products: 92 + 230 = 322.
For 23 × 14, calculate 23 × 4 = 92 and 23 × 10 = 230. Add the partial products: 92 + 230 = 322. The 1 in 14 represents ten, which is why its partial product is 230, not 23.
Align partial products by place value. Before adding, check the regrouping in each multiplication separately. An estimate such as 20 × 15 = 300 helps detect an answer that is much too small or large.
Work through one example aloud before independent practice. To check 18 + 7 = 25, calculate 25 − 7. If a word problem asks about meters or coins, include that unit and check whether the answer fits the situation.