Page 32 - SM Class 5 Inner.cdr

Table of Divisibility Test

Divisible By Rules of Divisibility

02 The last digit or the unit digit is even (0,2,4,6,8).
03 The sum of the digits is divisible by 3.

04 The last two digits are divisible by 4.
05 The unit digit or last digit is 0 or 5.
06 Number divisible by both 2 and 3.

07 The last digit is multiplied by 2 and subtracted from the
rest of the number. The result is either 0 or divisible by 7.
08 The last three digits are divisible by 8.

09 The sum of the digits is divisible by 9.
10 The unit digit is zero.
11 The sum of the even digits is subtracted from the sum of

the odd digits. The result is either 0 or divisible by 11.
12 Number divisible by both 3 and 4.

Example 2 :
1. Is 7248 is divisible (i) by 4, (ii) by 2 and (iii) by 8 ?
(i) The number 7248 has 48 on its extreme right side which is exactly divisible by 4. When we
divide by 4 we get 12.
Therefore, 7248 is divisible by 4.
(ii) The number 7248 has 8 on its unit place which is an even number so, 7248 is divisible by 2.
(iii) 7248 is divisible by 8 as 7248 has 248 at its hundred place, tens place and unit place
which is exactly divisible by 8.

E xercise 3.2

1. Which of the following numbers are divisible by 2, 5, 7 and 10 ?
a. 149 b. 19400 c. 720345

d. 125370 e. 3000000

2. Check whether the numbers are divisible by 4, 6, 9 or 12 ?
a. 23408 b. 100246 c. 34972

d. 150126 e. 58724 f. 19000
g. 43938 h. 846336

Prime Factorization

As every human being has a unique fingerprint. Similarly every number can
have a unique “factorprint ”.

32
Mathematics In Focus - 5