110
Making a number several times smaller
Textbook: Part 3, lesson 104, pp. 68–69
GoalMake a number several times smaller: tell “times fewer” from “fewer by”.
New words
making smaller · kamaytirishtimes fewer · marta kaminverse operation · teskari amaldiagram · sxema
Explanation
To make a number n times smaller we divide it by n. 12 made 3 times smaller is 12 : 3 = 4. Be careful: “3 times fewer” means divide, “3 fewer” means subtract. 12 made 3 less is 12 − 3 = 9. Making bigger and making smaller are inverse operations.
Worked examples
There are 8 stars, 2 times as many as diamonds: there are 8 : 2 = 4 diamonds.
30 made 3 times smaller is 10, and 30 made 3 less is 27.
Class activity
“Draw a diagram”: children draw the small quantity as 1 segment and the big one as several equal segments, then ask “how many times?”
Practice
1
Make 30 five times smaller.
6
2
Said read 6 tales. His grandfather read 4 times as many. How many tales did the grandfather read?
24
3
Father hoed 10 rows, which is 5 times as many as Aziz. How many rows did Aziz hoe?
2
4
Halim caught 6 fish. His father caught 2 times as many, and his grandfather 3 times fewer than his father. How many fish did the grandfather catch?
4
5
Make 24 smaller by 4.
20