Page 82 - ICSE Math 4

2. Write the fi rst fi ve mul ples of the following numbers.
(a) 7 (b) 11 (c) 14 (d) 8 (e) 6

th
3. Write the 4 and the 7 mul ples of the following numbers.
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(a) 12 (b) 18 (c) 4 (d) 16 (e) 5

4. Encircle the numbers which are mul ples of the given coloured numbers.

(a) 2 24 97 650 418
(b) 5 65 436 950 277
(c) 3 52 72 615 346

(d) 9 96 172 81 18

5. Find two common mul ples of the following numbers.

(a) 3 and 7 (b) 4 and 8 (c) 3, 6 and 9
Even and Odd Numbers

Even numbers are the mul ples of 2 or the numbers that are divisible by 2. They end with
0, 2, 4, 6 and 8. Numbers such as 2, 4, 6, 8, 10, 12, 14 and 16 are the fi rst few even numbers.

Odd numbers are the numbers that are not divisible by 2 and end with 1, 3, 5, 7 and 9.
Numbers such as 1, 3, 5, 7, 9, 11, 13 and 15 are the fi rst few odd numbers.

Mental Maths

1. Add and state whether the sum is even or odd. Top Tip
(a) 5 + 6 = _________ (b) 2 + 8 = _________
2 is one of the
2. Write True or False.
factors of all the
(a) Sum of two even numbers is even. even numbers.
(b) Sum of two odd numbers is odd.
(c) Sum of an even number and an odd number is odd.

Remember
Prime and Composite Numbers • 2 is the smallest prime number.

A prime number is a number that has only two • 2 is the only even prime number.
factors, i.e., 1 and the number itself. It cannot All other even numbers are
be divided exactly by any other number, except composite numbers.
1 and itself. • If two numbers have only 1 as a
common factor, they are known as
For example, numbers such as 2, 3, 5, 7, 11 and co-prime numbers.
13 are some of the prime numbers.
A number other than the prime number is called composite number. A composite number

has more than two factors apart from 1 and the number itself. It can be divided exactly by
its factors.
For example, numbers such as 4, 6, 8, 9 and 10 are some of the composite numbers.

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