41
Dividing a two-digit number by a one-digit number
Textbook: Part 2, lesson 41, pp. 7–9
GoalWhen dividing a two-digit number by a one-digit number, break the dividend into a convenient sum or difference.
New words
dividend · bo‘linuvchibreaking up · yoyishdifference · ayirmaquotient · bo‘linma
Explanation
To divide a bigger number, split it into two parts that are each easy to divide. 92 : 4 = (80 + 12) : 4 = 20 + 3 = 23. A difference also helps: 95 : 5 = (100 − 5) : 5 = 20 − 1 = 19. Each part must divide exactly by the divisor.
Worked examples
84 : 6 = (60 + 24) : 6 = 10 + 4 = 14.
144 : 9 = (180 − 36) : 9 = 20 − 4 = 16.
Class activity
“Break it up”: the teacher says 72 : 6. Children find a convenient split (72 = 60 + 12) on the board or in notebooks and give the quotient.
Practice
1
65 : 5 = ? (65 = 50 + 15)
13
2
76 : 4 = ? (76 = 80 − 4)
19
3
6 identical notebooks cost 78 thousand so‘m. How many thousand so‘m does one notebook cost?
13
4
96 apples were put equally into 8 baskets. How many apples are in each basket?
12