Review: multiplication, division and word problems
Multiplication and division are connected. A fact family such as 8, 9 and 72 gives 8 × 9 = 72, 9 × 8 = 72, 72 ÷ 8 = 9 and 72 ÷ 9 = 8. If a number is missing, use the family. Facts with tens use basic facts: 6 × 40 = 240 because 6 × 4 = 24. Word problems often have two steps. Karim saves 15 LE every week for 8 weeks: 8 × 15 = 120 LE. He buys a football for 95 LE, so 120 − 95 = 25 LE is left. For mass, remember 1,000 g = 1 kg. Six bags of rice of 2 kg each have 6 × 2 = 12 kg. Four packs of 250 g each have 4 × 250 = 1,000 g, which is 1 kg. Always write the unit: LE, g or kg.
| Tool | Use it for | Example |
|---|---|---|
| Fact family | a missing number | 8 × ? = 72, so 72 ÷ 8 = 9 |
| Tens fact | multiples of 10 | 6 × 40: 6 × 4 = 24, so 240 |
| Two steps | money problems | 8 × 15 = 120, then 120 − 95 |
| Items | Work | Mass |
|---|---|---|
| 6 bags, 2 kg each | 6 × 2 | 12 kg |
| 4 packs, 250 g each | 4 × 250 | 1,000 g = 1 kg |
Play shop. Make price tags between 5 LE and 100 LE for six things at home, using whole pounds. Ask a family member to buy three of them with 200 LE and tell you the total and the change. Then work it out yourself and check with addition. Finally weigh two bags of rice or sugar on a kitchen scale and find their total mass in kg and g.