Which of the following are factors of 3,435,864?
2
3
4
5
6
8
9
10
Which of the following are factors of 123,456,780?
2
3
4
5
6
8
9
10
What is the smallest 4-digit number that is divisible by 2, 3, 4, 5, 6, 8, 9, and 10?
Using only 1’s and 2’s, what is the smallest integer you can create which is divisible by both 3 and 8?
The digits of a number are all 8’s, and it is divisible by 9. What is the least positive integer that fits this
description?
What is the smallest positive integer that is divisible by 2 and 3 that consists entirely of 2’s and 3’s, with
at least one of each?
What is the smallest five-digit integer divisible both by 8 and by 9?
What is the remainder when 456,564,465,645 is divided by 6?
360 is divisible by both 8 and 9. How many integers less than 360 are also divisible by both 8 and 9?
Divisibility by 11
Multiplying
by 11
To find out if a number is divisible
by eleven:
Sum the alternating digits. Subtract these two sums. If the result is ZERO or is divisible by 11,
A+B
B+C
C+D
D
the number is divisible by 11. A
Examples:
495
9,835
14,806
918,291
What digit could fill in the blank to make 89,_43 divisible by 11?
What five-digit multiple of 11 consists entirely of 2’s and 3’s?
What is the largest five-digit multiple of 11?
How many three-digit multiples of 11 end in a 2?
Find the remainder when 1,234,567 is divided by 11.
Find the smallest positive integer greater than 90,000 that is divisible by 11.
Side Note: Multiplying by 11
A (A+B) (B+C) (C+D) D
504 x 11 = ____________
1723 x 11 = ___________
34,512 x 11 = _______________
2/9 –
Divisibility Rules
Monthly Challenge #4
Warm Up 10
2/16 -- Cookies
2/23 -- GCF/LCM
Workout 5
3/2 --
Determining Factors in a Number
Warm Up 11
3/9 --
Monthly Challenge #5
Warm Up 12
3/16 -- Workout #6
3/23 -- Celebration