Vocabulary
What is a sum?
The answer when you add, what you get when you combine addends.
What's missing: 9 + _ = 10
1
5 + 5 =
10
Find the sum: 7+6=
13
What should I try to do first when I see 3 numbers to add? (which strategy...)
Make a 10!
What is an Addend?
The parts you put together when you add.
What's missing: 7 + _ = 10
3
7 + 7 =
14
Find the sum: 4+5=
9
What is a strategy I should try when I need to add 3 numbers together?
Make a ten
Doubles
Near Doubles
What is a "doubles fact" in addition?
4+4
1+1
When the addends are the same.
What's missing: 2 + _ = 10
8
What doubles fact makes 16?
8 + 8
Find the sum: 9+8=
17
Find the sum: 7 + 4 + 3 =
14
What is a "near double"?
A near double is when the addends are one away from being a double fact.
Example: 6+7 or 5+4
What's missing: 4 + _ = 10
6
Is this a doubles fact: 8+7
Defend your answer.
No, because a doubles fact has two addends that are the same.
How can near doubles help me add?
I can think of the double fact it's near, and take away 1 or add 1 to find the sum.
Find the sum: 6 + 7 + 6 =
19