Page 26 - NUMINO TG_6A

01What Do We Have in Common? Unit

Sample Answers Board B If students have difficulty with the game have
234567 them use method 1 or method 2 to create a
Board A list of the prime factors.
234567 10 12 9
5 30 6 Example: Board A
236 3 36 20 Students should look for the most
8 12 16 Numbers chosen: 2 , 5 common group of primes.
18 24 30 In board A, 2 occurs 8 times, 3 occurs 5
Board D times, 2 2 occurs 4 times, 5 occurs 1
Numbers chosen: 2 , 3 234567 time, 2 3 occurs 5 times, 7 occurs 0
times, and 2 2 2 occurs 2 times.
2, 6 15 40 48 You can eliminate prime groups that occur
60 90 45 less than 3 times.
Board C 30 18 24
235678 Numbers chosen: 2 , 3 23
23
3 15 48 3, 5
9 8 32 8 12
16 6 24 1. What Do We Have in Common? 7 2, 2, 2 2, 2, 3

Numbers chosen: 2 , 8 18 24
2, 3, 3 2, 2, 2, 3

Additional Divisibility Rules

7: Double the last digit and subtract it from the rest of the number; if that number is divisible by 7 the

number is divisible by 7.

Example: Is 69 divisible by 7?

Step 1: 9 2 18

Step 2: 69 18 42

Step 3: 42 7 6; Yes

8: The last 3 digits are divisible by 8.

11: Subtract and add alternate digits from left to right; divide the sum by 11.

Example: Is 9296606 divisible by 11?

9 2 9 6 6 0 6 22; Yes 6A Unit 01 009