A smaller answer
Show on a big screenYou have 8 m of cloth and use 0.5 of it. How much is used?
Loading lab…
The rule
4 m is used. 0.5 is half, and half of 8 is 4.
The multiplier is the number you multiply by. Here every number is above 0.
Look at the multiplier. Below 1, the answer is smaller than the other number. Above 1, the answer is bigger. At 1, nothing changes.
Why? A number below 1 takes only part of the other number.
Check with a rough size, a quick near guess. 3.9 × 0.5 is about half of 4, which is 2. Working it out: 39 × 5 = 195. Two places give 1.95.
| You multiply by | The answer is | Example |
|---|---|---|
| A number below 1 | Smaller than the other number | 8 × 0.5 = 4 |
| 1 | The same as the other number | 8 × 1 = 8 |
| A number above 1 | Bigger than the other number | 8 × 1.5 = 12 |
Two numbers below 1 give an answer smaller than both. 0.6 × 0.5 = 0.3, because 6 × 5 = 30 and two places give 0.30.
One number above 1 and one below? The answer is between them. 8 × 0.5 = 4, and 4 is between 0.5 and 8.
Try the lab to finish this lesson.