119
Dividing by 9
Textbook: Part 3, lesson 112, pp. 86–87
GoalDivide by 9.
New words
dividing by 9 · 9 ga bo‘lishgroup · guruhrow · qatorquotient · bo‘linma
Explanation
36 : 9 = 4, because 4 × 9 = 36. The table for dividing by 9: 9 : 9 = 1, 18 : 9 = 2, 27 : 9 = 3, ... 90 : 9 = 10. To divide we use the times table: “What do we multiply 9 by to get 63?” – by 7.
Worked examples
36 children split into groups of 9 make 36 : 9 = 4 groups.
A 45 dm ribbon made 9 times shorter gives a piece of 45 : 9 = 5 dm.
Class activity
“Groups of nine”: children form groups of 9 and count how many groups 36 or 27 children make, then write the expression.
Practice
1
36 children like football. They were split into groups of 9. How many groups were made?
4
2
Salima planted flowers 9 to a row. How many rows did she use for 27 irises and 18 other flowers in total?
5
3
81 : 9 = ?
9
4
A picture is 8 dm long and 5 dm wide. What is its perimeter in dm?
26
5
What is the area of this picture in dm²?
40