Divisible by 3
A number is divisible by 3, if the sum of its all digits is
a multiple of 3 or divisibility by 3.
Consider the multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, .........
Number
|
Sum of the Digits
|
12 15 18 21 24 27
|
1 + 2 = 3 1 + 5 = 6 1 + 8 = 9 2 + 1 = 3 2 + 4 = 6 2 + 7 = 9
|
In each case the sum of the digits is divisible by 3.
A number is divisible by 3 if the sum of its digits is divisible by 3.
1. Let us consider the following numbers to find whether the numbers are divisible or not divisible by 3:
(i) 54
Sum of all the digits of 54 = 5 + 4 = 9, which is divisible by 3.
Hence, 54 is divisible by 3.
(ii) 73
Sum of all the digits of 73 = 7 + 3 = 10, which is not divisible by 3.
Hence, 73 is not divisible by 3.
(iii) 137
Sum of all the digits of 137 = 1 + 3 + 7 = 11, which is not
divisible by 3.
Hence, 137 is not divisible by 3.
(iv) 231
Sum of all the digits of 231 = 2 + 3 + 1 = 6, which is
divisible by 3.
Hence, 231 is divisible by 3.
(v) 194
Sum of all the digits of 194 = 1 + 9 + 4 = 14, which is not
divisible by 3.
Hence, 194 is not divisible by 3.
(vi) 153
Sum of all the digits of 153 = 1 + 5 + 3 = 9, which is
divisible by 3.
Hence, 54 is divisible by 3.
(vii) 171
Sum of all the digits of 171 = 1 + 7 + 1 = 9, which is
divisible by 3.
Hence, 171 is divisible by 3.
(viii) 277
Sum of all the digits of 277 = 2 + 7 + 7 = 16, which is not
divisible by 3.
Hence, 277 is not divisible by 3.
(ix) 276
Sum of all the digits of 276 = 2 + 7 + 6 = 15, which is
divisible by 3.
Hence, 276 is divisible by 3.
(x) 179
Sum of all the digits of 179 = 1 + 7 + 9 = 17, which is not
divisible by 3.
Hence, 179 is not divisible by 3.
2. Is 756 divisible by 3?
7 + 5 + 6 = 18 (18 is a multiple of 3)
Hence 756 is divisible by 3
We can verify that 756 is divisible by 3 by actual division.
3. In the number 46 * 8782, replace * by (i) a smallest digit and (ii) a largest digit to make it divisible by 3.
Solution:
The sum of the digits in the number 46 * 8782 = 4 + 6+ 8 + 7 + 8 + 2 = 35
(i) The number next to 35 which is divisible by 3 = 36.
Therefore, * is to be replaced by 1 i.e., 36 - 35 = 1;
Hence, the smallest digit 1 replaces * so as to make the number 4618782 divisible by 3.
(ii) We know that 35 + 7 = 42, which is divisible by 3.
Hence, the required largest digit 7 replaces * so as to make the number 4678782 divisible by 3.
Worksheet on Divisible by 3:
1. Fill the correct lowest possible digit in the blank space to make the number divisible by 3.
(i) 16335_
(ii) 20_984
(iii) 8422_1
(iv) 749_261
(v) 999_32
(vi) 1_7073
Answer:
1. (i) 3
(ii) 4
(iii) 1
(iv) 1
(v) 1
(vi) 3
2. Which of the following numbers are divisible by 3?
(i) 875
(ii) 729
(iii) 3647
(iv) 8504
(v) 111
(vi) 3732
(vii) 6425
(viii) 963
Answer:
2. (ii) 729
(v) 111
(vi) 3732
(viii) 963
You might like these
Highest common factor (H.C.F) of two or more numbers is the greatest number which divides each of them exactly. Now we will learn about the method of finding highest common factor (H.C.F). Steps 1: Find all the factors of each given number. Step 2: Find common factors of the
Prime factorisation or complete factorisation of the given number is to express a given number as a product of prime factor. When a number is expressed as the product of its prime factors, it is called prime factorization. For example, 6 = 2 × 3. So 2 and 3 are prime factors
We will discuss here about multiples and factors and how they are related to each other. Factors of a number are those numbers which can divide the number exactly. For example, 1, 2, 3 and 6 are
A number is divisible by 4 if the number is formed by its digits in ten’s place and unit’s place (i.e. the last two digits on its extreme right side) is divisible by 4. Consider the following numbers which are divisible by 4 or which are divisible by 4, using the test of
Divisible by 5 is discussed below: A number is divisible by 5 if its units place is 0 or 5. Consider the following numbers which are divisible by 5, using the test of divisibility by
Divisible by 6 is discussed below: A number is divisible by 6 if it is divisible by 2 and 3 both. Consider the following numbers which are divisible by 6, using the test of divisibility by 6: 42
Divisible by 8 is discussed below: A number is divisible by 8 if the numbers formed by the last three digits is divisible by 8. Consider the following numbers which are divisible by 8
Divisible by 7 is discussed below: We need to double the last digit of the number and then subtract it from the remaining number. If the result is divisible by 7, then the original number will also be
A number is divisible by 9, if the sum is a multiple of 9 or if the sum of its digits is divisible by 9. Consider the following numbers which are divisible by 9, using the test of divisibility by 9:
Divisible by 10 is discussed below. A number is divisible by 10 if it has zero (0) in its units place. Consider the following numbers which are divisible by 10, using the test of divisibility by 10:
The least common multiple (L.C.M.) of two or more numbers is the smallest number which can be exactly divided by each of the given number. The lowest common multiple or LCM of two or more numbers is the smallest of all common multiples.
What are multiples? ‘The product obtained on multiplying two or more whole numbers is called a multiple of that number or the numbers being multiplied.’ We know that when two numbers are multiplied the result is called the product or the multiple of given numbers.
All the even and odd numbers between 1 and 100 are discussed here. What are the even numbers from 1 to 100? The even numbers from 1 to 100 are:
What are the prime and composite numbers? Prime numbers are those numbers which have only two factors 1 and the number itself. Composite numbers are those numbers which have more than two factors.
Worksheet on divisibility rules will help us to practice different types of questions on test of divisibility by 2, 3, 4, 5, 6, 7, 8, 9, 10 and 11. We need to use the divisibility rules to find whether the given number is divisible by 2, 3, 4, 5, 6, 7, 8, 9, 10 and 11.
● Divisibility Rules.
Properties of Divisibility.
Divisible by 2.
Divisible by 3.
Divisible by 4.
Divisible by 5.
Divisible by 6.
Divisible by 7.
Divisible by 8.
Divisible by 9.
Divisible by 10.
Divisible by 11.
Problems on Divisibility Rules
Worksheet on Divisibility Rules
5th Grade Math Problems
From Divisible by 3 to HOME PAGE
Didn't find what you were looking for? Or want to know more information
about Math Only Math.
Use this Google Search to find what you need.
Share this page:
What’s this?
New! Comments
Have your say about what you just read! Leave me a comment in the box below. Ask a Question or Answer a Question.