Raven pins her clipboard to the Numbers Desk. "Field Day supply list. What we have, and what each station needs."
Rocket reads the first row. "Ribbon: 7 1/2 meters. Each finish line needs 1 1/4 meters." He frowns. "That is a lot of folding."
"Then do not fold," says Nova, hovering by the clipboard. "Every row is a division problem."
"What do you notice about the two numbers in each row?" asks Raven.
"One is what we have, one is what each station takes," Rocket says. "Have, divided by each."
He scribbles. "15/2 ÷ 5/4. Flip, multiply, 60/10. Six finish lines!"
Nova hums. "Now do the whole list before you cut any ribbon."
These are the crew's own numbers for their Field Day, written in Raven's log. Each row asks: how many stations can we set up?
| Supply | We have | Each station needs | Stations |
|---|---|---|---|
| Ribbon | 7 1/2 meters | 1 1/4 meters | ? |
| Blue paint | 2 2/3 cups | 1/3 cup | ? |
| String | 5 meters | 5/8 meter | ? |
| Lemon juice | 3/4 cup | 1/8 cup | ? |
Mixed numbers go improper first. 7 1/2 = 15/2 and 1 1/4 = 5/4.
Then flip and multiply: 15/2 ÷ 5/4 = 15/2 × 4/5 = 60/10 = 6. Six finish lines.
Blue paint: 2 2/3 = 8/3, and 8/3 ÷ 1/3 = 8/3 × 3/1 = 8 signs.
Sometimes you know the number of groups and want the size of each group.
Share 3/4 cup of paint equally among 3 signs. 3/4 ÷ 3 = 3/4 × 1/3 = 3/12 = 0.25 cup for each sign.
Dividing by a whole number works the same way. The reciprocal of 3 is 1/3.
| Sentence | True or false? |
|---|---|
| 7 1/2 ÷ 1 1/4 = 6 | ? |
| 5 ÷ 5/8 = 8 | ? |
| 3/4 ÷ 3 = 1/4 | ? |
| 2 2/3 ÷ 1/3 = 6 | ? |
Good planning. Tomorrow you find fraction division in everyday life and review the whole week.