Factors
List all the factors of 40.
1, 2, 4, 5, 8, 10, 20, 40.
List the first 5 multiples of 9.
9, 18, 27, 36, 45.
List all the prime numbers between 1 and 20.
2, 3, 5, 7, 11, 13, 17, 19.
Determine if the following number is divisible by 2 and 4.
436
436 is divisible by 2 and 4.
2 - even number.
4 - the numbers formed by the last 2 digits (36) is divisible by 4.
At the gym, Sam swims every 6 days, runs every 4 days, and cycles every 16 days. If she did all three activities today, in how many days will she do all three activities again on the same day?
Run: 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48
Swim: 6, 12, 18, 24, 30, 36, 42, 48, 54
Cycle: 16, 32, 48
Sam will do all 3 again in 48 days.
List all the factors of 60.
1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60.
List the first 6 multiples of 12.
12, 24, 36, 48, 60, 72.
Describe what a composite number is.
They are divisible by more than just 1 and itself.
Determine if the following number is divisible by 3 and 5.
125
125 is divisible by 5, but not by 3.
3 - sum of all digits (8) is not divisible by 3.
5 - last digit is a 5 or 0.
Cups are sold 5 to a package and plates are sold 8 to a package. If you want to have the same number of each item for a party, what is the least number of packages of each you need to buy?
LCM
Cups 5, 10, 15, 20, 25, 30, 35, 40
Plates 8, 16, 24, 32, 40
To end up with 40 of each, you will need 8 packages of cups and 5 packages of plates.
Find the GCF of 16 and 38.
16: 1, 2, 4, 8, 16
38: 1, 2, 19, 38
GCF = 2
Find the LCM of 7 and 8.
7: 7, 14, 21, 28, 35, 42, 49, 56
8: 8, 16, 24, 32, 40, 48, 56
LCM = 56
Determine which of the following is a prime number:
50 51 55 56 59
59 is prime.
50 - divisible by 2, 5, 10
51 - divisible by 3
55 - divisible by 5
56 - divisible by 2, 4, 7, 8
Determine if the following number is divisible by 4 and 9.
612
612 is divisible by 4 and 9.
4 - number formed by last 2 digits (12) is divisible by 4.
9 - sum of all digits (9) is divisible by 9.
A radio station is having a promotion in which every 4th caller receives a free concert ticket, and every 6th caller receives a limo ride. Which caller will be the first one to win both?
LCM
Concert tickets 4, 8, 12, 16, 20, 24
Limo ride 6, 12, 18, 24
The 12th caller will be the first person to win a concert ticket and limo ride.
Find the GCF of 100 and 144.
(Hint: Use factor T chart)
100: 1, 2, 4, 5, 10, 20, 25, 50, 100
144: 1, 2, 3, 4, 6, 8, 12, 18, 24, 36, 48, 72, 144
GCF = 4
Find the LCM of 2 and 11.
2: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22
11: 11, 22, 33, 44
LCM = 22
Determine whether 129 is prime or composite.
It is composite.
129 is divisible by 3 - the sum of its digits is 12.
Determine if the following number is divisible by 6.
439
6 - must be divisible by 2 and 3.
2 - 439 is not even
3 - sum of all digits (16) is not divisible by 3
Hengchuo has 15 oranges, 9 peaches and 18 pears. He wants to put all of the fruit into baskets with each basket having the same number of pieces of fruit in it. Without mixing the fruit, what is the greatest number of pieces of fruit Hengchuo can put in each basket? How many baskets of pears will he have?
GCF
(Hint: Use factor T chart)
Oranges: 1, 3, 5, 15
Peaches: 1, 3, 9
Pears: 1, 2, 3, 6, 9, 18
GCF = 3
Hengchuo can make baskets of 3. There will be 6 baskets of pears.
Find the GCF of 36, 64, and 96.
(Hint: Use factor T chart)
32: 1, 2, 4, 8, 16, 32
64: 1, 2, 4, 8, 16, 32, 64
96: 1, 2, 3, 4, 8, 12, 24, 32, 48, 96
GCF = 32
Find the LCM of 5, 8, and 10.
5: 5, 10, 15, 20, 25, 30, 35, 40
8: 8, 16, 24, 32, 40, 48
10: 10, 20, 30, 40
LCM = 40
Explain why 2 is the only even prime number.
2 is prime because it only has 2 factors, 1 and itself.
2 is a factor of ALL even numbers, therefore any even number larger than 2 will have at least one other factor (2).
Determine if the following number is divisible by 6 and 9.
18, 234
18, 234 is divisible by 6 and 9.
9 - sum of all digits (18) is divisible by 9.
6 - divisible by 2 and 3.
2 - even.
3 - sum of all digits (18) is divisible by 3.
There are 28 grade 6's and 42 grade 7's from registered to participate in a spelling bee. The quiz master divided the participants into the as many teams as they can, with the same number of grade 6's and 7's on each team. How many teams will there be? How many grade 6's and 7's are on each team?
GCF
(Hint: Use factor T chart)
Grade 6's: 1, 2, 4, 7, 14, 28
Grade 7's: 1, 2, 3, 6, 7, 14, 21, 42
There will be 14 teams.
Each time will have 2 grade 6's and 3 grade 7's.