29
Multiplying by a one-digit number (practice)
Textbook: Part 1, lesson 29, pp. 90–92
GoalPractise multiplying a multi-digit number by a one-digit number; money and currency problems.
New words
place with zero · nol xonachange in the rate · kurs o‘zgarishieuro cent · yevrosentproduct · ko‘paytma
Explanation
All places are multiplied in the same way. If the number has a 0 inside, the product 0 gets the carried number added to it and that is written down. When the exchange rate changes, the price in so‘m changes: change = amount of foreign money × change in the rate.
Worked examples
46 207 × 4: 7 × 4 = 28 (write 8, carry 2); 0 × 4 + 2 = 2; 2 × 4 = 8; 6 × 4 = 24 (write 4, carry 2); 4 × 4 + 2 = 18. Answer: 184 828.
503 760 × 6 = 3 022 560.
Class activity
“The rate changed”: yesterday’s and today’s dollar rates are written on the board. Children work out by how much the so‘m price of a 5-dollar item changed.
Practice
1
47 902 × 9 = ?
431118
2
436 758 × 2 = ?
873516
3
2 650 317 × 7 = ?
18552219
4
The dollar rate rose from 12 400 to 12 650 so‘m. By how many so‘m does the so‘m price of a 9-dollar shirt rise?
2250
5
How many euros are 4 700 cents? (1 euro = 100 cents)
47