﻿ Unit 2 Section 3 : Multiplication and Division

# Unit 2 Section 3 : Multiplication and Division

In this section we review multiplication and division. Again, you are not expected to use a calculator.

## Example 1

Calculate:

 (a) 41 × 10 (b) 4.712 × 100 (c) 62 ÷ 100 (d) 23.7 ÷ 10

## Example 2

Calculate:

 (a) 12 × 24 (b) 37 × 15

## Example 3

Calculate:

 (a) 4.7 × 5 (b) 6.4 × 2.3

## Example 4

Calculate:

 (a) 124 ÷ 4 (b) 615 ÷ 5

## Example 5

 A chocolate bar costs 32p. Calculate the cost of 7 chocolate bars.

## Exercises

Work out the answers to the questions below and fill in the boxes. Click on the button to find out whether you have answered correctly. If you are right then will appear and you should move on to the next question. If appears then your answer is wrong. Click on to clear your original answer and have another go. If you can't work out the right answer then click on to see the answer.
Question 1
Calculate:
 (a) 6 × 10 (b) 17 × 100 (c) 8 × 1000 (d) 14 × 10 (e) 321 × 10 (f) 4.2 × 10 (g) 3.6 × 100 (h) 14.7 × 10 (i) 0.461 × 100
Question 2
Calculate:
 (a) 4700 ÷ 10 (b) 360 ÷ 10 (c) 421 ÷ 10 (d) 16.8 ÷ 10 (e) 476 ÷ 100 (f) 5600 ÷ 100 (g) 56.2 ÷ 100 (h) 113.6 ÷ 100 (i) 0.652 ÷ 10
Question 3
Calculate:
 (a) 15 × 6 (b) 34 × 2 (c) 82 × 7 (d) 37 × 5 (e) 19 × 6 (f) 82 × 4 (g) 16 × 12 (h) 24 × 14 (i) 32 × 24 (j) 66 × 47 (k) 84 × 28 (l) 62 × 29
Question 4
Calculate:
 (a) 4.7 × 2 (b) 6.3 × 5 (c) 11.4 × 5 (d) 12.7 × 3 (e) 14.8 × 4 (f) 22.1 × 7 (g) 1.2 × 3.7 (h) 4.2 × 5.9 (i) 1.24 × 1.6 (j) 7.23 × 1.4 (k) 18.2 × 3.2 (l) 27.6 × 4.2
Question 5
Calculate:
 (a) 12 ÷ 4 (b) 81 ÷ 9 (c) 42 ÷ 7 (d) 24 ÷ 8 (e) 64 ÷ 8 (f) 45 ÷ 5 (g) 75 ÷ 5 (h) 86 ÷ 2 (i) 98 ÷ 7 (j) 128 ÷ 4 (k) 248 ÷ 4 (l) 497 ÷ 7 (m) 1917 ÷ 9 (n) 411 ÷ 3 (o) 855 ÷ 5
Question 6
Write out each of these calculations, filling in the missing numbers:
 (a) 6 × = 120 (b) ÷ 8 = 7 (c) 26 ×= 962 (d) ÷ 24 = 16
Question 7
Write one number at the end of each calculation to make it correct:
 (a) 6 × 5 = 3 × (b) 40 × 10 = 4 × (c) 5 × 30 = 25 × (d) 7000 ÷ 100 = 700 ÷ (e) 480 ÷ 20 = 2400 ÷ (f) 355 × 12 = 1420 ×
Question 8
A packet of crisps costs 32p. Calculate the cost of:
 (a) 3 packets (b) 7 packets (c) 25 packets
Question 9
A meal at a burger bar costs £2.95. Calculate the cost of:
 (a) 2 meals (b) 3 meals (c) 5 meals
Question 10
Joseph counts the number of sweets in a packet and find that there are 22.
How many sweets are there in total in:
 (a) 6 packets? (b) 100 packets? (c) 17 packets?
Question 11
Three brothers are given 102 football stickers by their uncle. If they share them equally, how many stickers will they each have?

stickers.

Question 12
Four children are paid £42.60 for working as gardeners. How much will they each have if they share the money equally?

Question 13
Stamps are 19p each. Gwyn wants to buy 9 stamps. He knows that he will have to pay less than £2.

(a) Write down how you can tell that he will have to pay less than £2 without working out the exact answer.

Because 9 stamps cost less thanstamps which cost £1.90, which is less than £2.

Note that there are other ways to tell that he will have to pay less than £2 without working out the exact answer.

(b) Gwyn buys 9 stamps at 19p each.
Without using a calculator, work out exactly how much he must pay.

Question 14
Gwen makes kites to sell. She sells the kites for £4.75 each.

(a) Gwen sells 26 kites.
Without using a calculator, work out how much money she gets for the 26 kites.

(b) Gwen has a box of 250 staples. She uses 16 staples to make each kite.
Without using a calculator, work out how many complete kites she can make using the 250 staples.

kites (withstaples left over).

Question 15
Here are some buttons on cards.
 10 round buttons on a card 5 star buttons on a card 2 flower buttons on a card

(a) Marc bought 9 cards of star buttons.
How many buttons did he buy altogether?

buttons

(b) Lee bought 8 cards of round buttons and 2 cards of flower buttons.
How many buttons did he buy altogether?

buttons

(c) Sally bought exactly 16 buttons. They were all the same sort of button.
What sort of buttons did Sally buy?

buttons

(d) Pat bought exactly 15 buttons. They were all the same sort of button.
What sort of buttons did Pat buy?

buttons

(e) Pinder wants to buy exactly 20 buttons. They must all be the same sort of button.
Pinder could buy:
2 cards of round buttons.
Write down two other possible answers for Pinder.

cards of buttons
or
cards of buttons

Question 16
Megan wants to plant 24 seeds.
She can plant them in 2 rows, with 12 seeds in each roll.

(a) Draw a diagram to show how she can plant 24 seeds in 3 rows, with the same number of seeds in each row.

(b) Draw a diagram to show a different way that Megan can plant 24 seeds in a different number of rows, with the same number of seeds in each row.

(c) Complete the table to show how many rows Megan can make with 24 seeds, and how many seeds there are in each row.

The number of rows in the table must increase in size order.

 Number of rows Number of seeds in each row 1 row 24 seeds in a row 2 rows 12 seeds in a row rows seeds in a row rows seeds in a row rows seeds in a row 8 rows 3 seeds in a row 12 rows 2 seeds in a row 24 rows 1 seed in a row

(d) Megan says: "I can plant 24 seeds in 5 rows, with the same number of seeds in each row."
Is Megan right?

Megan is wrong because 24 is not a multiple of 5,
or because she will be able to plant 4 rows of seeds with 4 seeds left over,
since 24 ÷ 5 = 4 remainder 4.