Page 103 - Start Up Mathematics_4

2. Colour the circles which are not the multiples of the numbers given in words.

(a) four 8 12 14 16 18 20 22

(b) six 18 20 24 26 28 30 42

(c) nine 27 36 46 56 72 90 111

(d) twelve 26 36 48 72 94 108 121
3. Solve and answer. Give a reason for your answer.

(a) Is 90 a multiple of 5? _________________________________________________
(b) Is 124 a multiple of 3? _________________________________________________
(c) Is 152 a multiple of 8? _________________________________________________

4. Skip count to complete the following sequence.
(a) multiples of 5 25, 30, 35, _______, _______, _______, _______

(b) multiples of 8 40, 48, 56, _______, _______, _______, _______
(c) multiples of 11 44, 55, 66, _______, _______, _______, _______

(d) multiples of 10 90, 100, 110, _______, _______, _______, _______
(e) multiples of 13 26, 39, 52, _______, _______, _______, _______
5. Find two common multiples of the following numbers.

(a) 5, 7 (b) 4, 8 (c) 3, 6, 9

Tests of Divisibility

Divisible by means when we divide one number by another number, no remainder is left. For
example, 14 is divisible by 2 because 14 ÷ 2 = 7 and no remainder is left. 13 is not divisible
by 2 because 13 ÷ 2 = 6 with remainder 1.
Let’s see some divisibility tests which help us to know if one number is divisible by another,
without having to do too much calculations.

Divisible by Rule Examples

2 A number is divisible by 2, if the digit at its ones place 128 (8 is even) 
is even. 129 (9 is not
even) 

3 A number is divisible by 3, if the sum of its digits is 27 (2 + 7 = 9) 
divisible by 3. 28 (2 + 8 = 10) 
5 A number is divisible by 5, if the digit at its ones place 175 
is 0 or 5. 176 
10 A number is divisible by 10, if the digit at its ones place 250 
is 0. 251 

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