0
Add your answer:
Earn +20 pts
What do you notice about the sum of the digits for each multiple of 9?
That they add up to 9
How do the digits in each product relate to the factor 9?
If they are multiples of 9, the digits add up to a multiple of 9.
Why do no digits of a prime number add up to 9?
Because they're in multiples of three - a quick way to tell if a number is a multiple of three is to add up the digits and see if the digits add up to a multiple of three e.g 576, 5+7+6=18, 1+8=9, 9 is a multiple of three
Name the 2 digit multiple of 8 whose digits add up to 10?
64
What is a two digit multiple of 7 that it's digits add up to 8?
15
What do you notice about the sum of the digits for each multiple of 9?
That they add up to 9
How do the digits in each product relate to the factor 9?
If they are multiples of 9, the digits add up to a multiple of 9.
Why do no digits of a prime number add up to 9?
Because they're in multiples of three - a quick way to tell if a number is a multiple of three is to add up the digits and see if the digits add up to a multiple of three e.g 576, 5+7+6=18, 1+8=9, 9 is a multiple of three
When can you say that the number is divisible by 3?
When its digits add up to a multiple of 3.
Is 990 divisible by 3?
Any number whose digits add up to a multiple of 3 is divisible by 3. Since the digits of 990 add up to 18, this is a multiple of 3.The sum itself: 990 / 3 = 330
How do you find out if a number is a multiple of 3?
you add up the digits, and if the sum is a multiple of 3, then the number is divisible by 3!
What is the 2 digit multiple of 8 whose digits add up to 10?
64
Is 164 divisible by 3 how do you now?
No. The digits don't add up to a multiple of 3.
Is 1673 divisible by 9?
The digits add up to 17, which is not a multiple of 3. So no.
How do you find out what is divisible by 3?
Add up the digits in the number. If the total is a multiple of 3, the entire number will be a multiple of 3.
What is a two digit multiple of 5 whose digits add up to 13?
The number is 85.
What number is a factor of 36 and it is a multiple of 3 and as 2 digits and they add up to three?
12
