Prime Time Study Guide Test-Monday, Sept. 21 and Tuesday, September 22
It is a BIG test. It is worth 100 points. You need to know your multiplication facts, know a prime number, and you must know the difference between factors of a number (factors are always smaller than the number, factors are what you multiply to get that product) and multiples of a number (multiples are that number or larger, they are what you get when you multiply the number by 1, 2, 3, 4, etc.).
You must be able to:
5. If you eat oatmeal every 5 days, a hamburger every 7 days, and yogurt every 3 days, if you had all three today, how many days until you have all three again (you must find the LCM of 3 numbers). 35 days.
Show how you work. I would list multiples of the numbers.
5 7 3
5 7 3
10 14 6
15 21 9
20 28 12
25 35 15
30 42 18
35 49 21
40 56 24
45 63 27
30
33
35
7. 32 42
2 x 16 2 x 21
2 x 8 3 x 7
2 x 4
2 x 2
Remember, in real class, you ALWAYS circle the prime numbers. Here I had to highlight them.
So the factor string for 32 is 2 x 2 x 2 x 2 x 2 42 is 2 x 3 x 7
I CAN’T GET MY VENN DIAGRAM TO WORK. YOU HAVE EXAMPLES IN YOUR BINDER.
So a 2 is in both factor strings and one 2 would go into the exclusive GCF club (Greatest Common Factor Club), or shared part of the circles. Four 2s would go into the circle for 32 only. 3 and 7 would go into the circle for 42.
The GFC is everything inside the shared part multiplied, this time it is only 2. The GCF of 32 and 42 is 2.
The LCM (Least Common Multiple) is found by multiplying ALL the digits in both circles (including the shared portion), or 2x2x2x2(from the 32 circle only)x2(from the shared part)x3x7(from the 42 circle only) (which is 32 x 3 x 7 = 672). So the LCM of 32 and 42 is 672.
8. Remember: Parenthesis Exponent Multiplication Division Addition Subtraction - I’ll highlight each step I’m doing
6 (3+2) - 4 4 + (2-1) x (2+2) 6 x 3 - 4(2) / 2
6(5) - 4 4 + 1 x (2+2) 18 - 4(2) / 2
30 - 4 4 + 1 x 4 18 - 8 / 2
26 4 + 4 18 - 4
8 14
Always do ONE step at a time.
It is a BIG test. It is worth 100 points. You need to know your multiplication facts, know a prime number, and you must know the difference between factors of a number (factors are always smaller than the number, factors are what you multiply to get that product) and multiples of a number (multiples are that number or larger, they are what you get when you multiply the number by 1, 2, 3, 4, etc.).
You must be able to:
- Choose a composite number and decompose it using the distributive property.
- Insert parentheses and/or addition or multiplication signs to make an equation true.
- Be able to list all the factor pairs that are possible for a given number (this is NOT using a T-Chart to list all the factors).
- Be able to do a problem like the Snack Bag problem with 3 items. There isn't an example on the blog. Could not get it to work tonight.
- Find the LCM to determine when three events will happen at the same time (Ferris Wheel Problem).
- Rewrite given problems using the distributive property from expanded to factored and factored to expanded form.
- Find the LCM and GCF for two numbers using prime factorization.
- Use Order of Operations (PEMDAS) to solve multistep problems.
- When given a rectangle model of the Distributive Property, give the factored and expanded form of the problem. If given a factored or expanded form of a problem, draw and label a rectangle model for it. There isn't an example on the blog for this, I couldn't make it work tonight.
- & 6. 2( 3+2) Factored form (2x3)+(2x2) Expanded form Specific for #1: 20=16+4=(2x8)+(2x2)
- 3 9 2 5 = 22 3 + 9 + (2 x 5) = 22
- Factor pairs for 48= (1, 48) (2, 24) (3, 16) (4, 12) (6, 8) (8,6) (12, 4) (16, 3) (24, 2) (48, 1)
- No example here. My Google Classroom has a study guide with it.
5. If you eat oatmeal every 5 days, a hamburger every 7 days, and yogurt every 3 days, if you had all three today, how many days until you have all three again (you must find the LCM of 3 numbers). 35 days.
Show how you work. I would list multiples of the numbers.
5 7 3
5 7 3
10 14 6
15 21 9
20 28 12
25 35 15
30 42 18
35 49 21
40 56 24
45 63 27
30
33
35
7. 32 42
2 x 16 2 x 21
2 x 8 3 x 7
2 x 4
2 x 2
Remember, in real class, you ALWAYS circle the prime numbers. Here I had to highlight them.
So the factor string for 32 is 2 x 2 x 2 x 2 x 2 42 is 2 x 3 x 7
I CAN’T GET MY VENN DIAGRAM TO WORK. YOU HAVE EXAMPLES IN YOUR BINDER.
So a 2 is in both factor strings and one 2 would go into the exclusive GCF club (Greatest Common Factor Club), or shared part of the circles. Four 2s would go into the circle for 32 only. 3 and 7 would go into the circle for 42.
The GFC is everything inside the shared part multiplied, this time it is only 2. The GCF of 32 and 42 is 2.
The LCM (Least Common Multiple) is found by multiplying ALL the digits in both circles (including the shared portion), or 2x2x2x2(from the 32 circle only)x2(from the shared part)x3x7(from the 42 circle only) (which is 32 x 3 x 7 = 672). So the LCM of 32 and 42 is 672.
8. Remember: Parenthesis Exponent Multiplication Division Addition Subtraction - I’ll highlight each step I’m doing
6 (3+2) - 4 4 + (2-1) x (2+2) 6 x 3 - 4(2) / 2
6(5) - 4 4 + 1 x (2+2) 18 - 4(2) / 2
30 - 4 4 + 1 x 4 18 - 8 / 2
26 4 + 4 18 - 4
8 14
Always do ONE step at a time.