Use a Number Line to Add
Add in Any Order
Use a Number Line to Subtract
Use Related Facts to Add and Subtract
Fact Families
Missing Addends
100
When you use a number line to add, what number should you begin with?
A. Smaller number B. Greater (Larger) number
B. Greater (Larger) number
100
What does it mean to "add?"
When you add you join addends together to get the sum.
100
I had 11 beach balls. I gave 2 away. Where do I begin counting back on this number line? Where do I stop?
On this number line you begin counting on number 11. You would count back and end up on number 9.
100
What is an addend?
An addend is any number you add.
100
What do you call facts that use the same numbers?
Facts that use the same numbers are called fact families.
100
What does it mean when you have a missing addend in an addition number sentence?
It means you have to use a related subtraction fact to find the missing addend because it was not given to you. (It's an addend that is not seen in the number sentence).
200
What is this picture called?
The picture is called a Number Line.
200
Can you add the same numbers in any order and get the same answer?
Yes.
200
Can you use a number line to add AND subtract?
Yes, you can use a number line to add and to subtract.
200
Related facts use the same____________?
Numbers
200
What are the numbers in this fact family?
The numbers in this fact family are 6, 8, and 14.
200
The butterfly has 7 spots on the left wing. He has 11 spots in all. Count on and say how many spots are missing.
(8, 9, 10, 11)
There are 4 spots missing.
300
How does a number line help you add?
You begin counting on the "starting number" and "count on" by making one jump for how many you are adding. Where you land is your answer (the sum).
300
Tell me two ways to add the following problem. Give the answer.
You have 5 fish swimming. Then 2 fish join them. How many fish do you have?
5 + 2 = 7
2 + 5 = 7
300
Do you "count on" or "count back" when using a number line to subtract?
When using a number line to subtract you "count back."
300
If 12 - 5 = 7 then _____ + 5 = 12
7
300
Add and subtract. Complete the fact family.
3 + 5 = ___ 8 - 5 = ___
5 + 3 = ___ 8 - 3 = ___
3 + 5 = 8 8 - 5 = 3
5 + 3 = 8 8 - 3 = 5
300
Use related facts to help you find the missing addend.
400
In this problem, how many hops do you have to make on your number line to find the answer? Explain.
7 + 5 =
To find the answer on the number line you have to make 5 hops. You begin at the number 7 and hop forward 5 times to get the answer.
400
Write two ways to add. Solve the problem.
Greg walks up 7 steps to get to his apartment. Bill walks up 8 steps to get to his apartment. How many steps do they walk up in all (total)?
7 + 8 = 15
8 + 7 = 15
They walk up 15 steps in all.
400
The answer to a subtraction problem is called the
A. Sum. B. Difference
B. Difference
400
Can related facts help you add and subtract? Explain.
Yes. Related facts use the same numbers. If you know the answer to the addition (or subtraction) fact you will know the answer to the subtraction (or addition) fact. (For example, if you know that 5 - 1 = 4, you know that 4 + 1 = 5).
400
Which one is the fact family? Explain.
A. B.
2 + 3 = 5 4 - 2 = 2 7 + 8 = 15 15 - 8 = 7
3 + 1 = 4 5 - 1 = 4 8 + 7 = 15 15 - 7 = 8
B.
A fact family only uses 3 numbers.
"A" has more than 3 numbers.
"B" only has three numbers; 7, 8, and 15.
400
You can find missing addends by ________________.
You can find the missing addends by subtracting.
500
In this problem, which number should you begin with on your number line? Explain.
1 + 8 = 9
In this problem you should begin with the number 8. You should begin with the greater number so you make less (fewer) hops and hop forward one time to get the sum (answer).
500
Say the addends. Then say the sum.
2 + 4 = 6
4 + 2 = 6
500
Can you subtract a larger number from a smaller number? Explain.
No. You cannot take a larger number away from a smaller number. (Ex. You can't take 8 slices of pizza away from someone who only has 1 slice of pizza).
500
16 - 7 = 9
9 + 7 = 16
500
A fact family is a group of four related addition and subtraction facts that use the same three numbers.
True or False
True
500
How do you use subtraction to find a missing addend in an addition problem?
You subtract the sum by the known addend. For example, in the following problem you subtract 7 from 12.
When I am added to 7, the sum is 12. What am I?
12 - 7 = 5.