MATH 5 ( IST MONTHLY 2024-25)

What is the divisibility rule for 5?

• The digits must add up to 10.

• The last digit needs to be a 5 or 0.

• The sum of the digits need to be divisible by 5.

• The last digit can only be a 5.

Is 525 divisible by 5?

• Yes

• No

All of these numbers are divisible by 5 except for...

• 
  75,395

• 984,940

• 222,222,235

• 8,943,892

Is 1,284,604 divisible by 2?

• 
  Yes, because the sum of the digits is 20, which is an even number

• No, because 4 is an odd number

• Yes, because 4 is an even number

• No, because the it is not divisible by 3

What is the divisibility rule for 3?

• Add up the digits. The sum must be an even number

• The digits must add up to 9.

• The last digit must be a 3.

• Add up the digits. The sum must be a multiple of 3.

Is 81 divisible by 3?

• 
  Yes, because the sum of the digits is 9, a multiple of 3

• No, because 81 is an odd number

• Yes, because 81 is an odd number

• No, because 81 does not end in 3

2520 is divisible by 6 because:

• It is divisible by 2 (even) and 5 (ends in a 0 or 5)

• The sum of the digits is 12, a multiple of 6

• It's divisible by 2 (even) and 3 (sum of digits is a multiple of 3)

• 
  The sum of the digits is even

What is the divisibility rule for 4?

• The sum of the digits must be a multiple of 4

• The last two digits must form a number that is a multiple of 4

• The number must be divisible by 2 and 3.

• The number must end in 0, 2, or 4

A number is divisible by 10 if

• It is even

• 
  It ends in 0

• 
  It ends in 0 or 5

• The sum of the digits is a multiple of 10

252 is divisible by 9 because:

• The number is divisible by 2 and 3

• The sum of the digits is a multiple of 9.

• The sum of the digits is a multiple of 3

• The sum of the digits is even.