4
Review: multiplication
Textbook: Part 1, lesson 4, pp. 13–15
GoalReview multiplication and division, finding an unknown factor and the order of operations.
New words
product · ko‘paytmafactor · ko‘paytuvchiquotient · bo‘linmaorder of operations · amallar tartibi
Explanation
Multiplication is repeated addition: 6 + 6 + 6 + 6 = 6 × 4. To find an unknown factor, divide the product by the known factor. In an expression we do brackets first, then multiplication and division, and finally addition and subtraction.
Worked examples
5 + 4 × 6 = 5 + 24 = 29.
(36 − 8) : 7 = 28 : 7 = 4.
Class activity
“Table ball”: children stand in a circle. The teacher tosses a ball and says “7 × 8”; the child who catches it answers, then names another problem and passes the ball on.
Practice
1
7 × 8 = ?
56
2
63 : 9 = ?
7
3
6 × x = 54. Find x.
9
4
A hall has 9 rows with 4 seats in each. How many seats are there?
36
5
Calculate: 30 − 6 × 4.
6