107
The 5 times table
Textbook: Part 3, lesson 101, pp. 62–63
GoalKnow the 5 times table; use multiplication in price and perimeter problems.
New words
the 5 times table · 5 ga ko‘paytirish jadvalipentagon · beshburchakpack · qadoqcheaper · arzon
Explanation
The 5 times table comes from counting in fives: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50. The perimeter of a pentagon with equal sides is a × 5. In price problems we multiply the price of one item by the number of items and compare with the price of a pack.
Worked examples
If a printer prints 5 sheets a minute, in 5 minutes it prints 5 × 5 = 25 sheets.
A regular pentagon with side 6 cm has perimeter 6 × 5 = 30 cm.
Class activity
“The shop”: in a play shop children buy 5 items. They set the price of an item and calculate the total for 5 items by multiplying.
Practice
1
5 × 8 = ?
40
2
A pentagon has all sides 6 cm. What is its perimeter in cm?
30
3
A broken line has 7 links of 5 cm each. How long is it in cm?
35
4
A square has side 5 dm. What is its area in dm²?
25
5
One carton of juice costs 3 thousand so‘m and a pack of 5 costs 14 thousand. By how many thousand so‘m is the pack cheaper than 5 single cartons?
1