Math Words and Ideas
Addition Combinations
Math Words
• sum
(page 1 of 4)
One of your goals in math class this year is to
review and practice all the addition combinations
up to 10 ! 10.
10 + 10 =
2+7=
7+2=
4+6=
6+4=
3+3
=
5+8=
8+5=
Learning Two Combinations at a Time
These two problems look different, but they have the
same sum.
8
!
3
3
!
8
When you know that 8 ! 3 " 11, you also know that
3 ! 8 " 11.
You’ve learned two addition combinations!
Why do these two problems have the same answer?
7!2"9
2!7"9
16 sixteen
Math Words and Ideas
Addition Combinations
(page 2 of 4)
A helpful way to learn addition combinations is to think
about one category at a time. Here are some categories
you may have seen before. You probably already know
many of these combinations.
Make 10 Combinations
2 ! 8 " 10
8 ! 2 " 10
3 ! 7 " 10
7 ! 3 " 10
4 ! 6 " 10
6 ! 4 " 10
Doubles Combinations
6 ! 6 " 12
7 ! 7 " 14
8 ! 8 " 16
5 ! 10 " 15
10 ! 5 " 15
6 ! 10 " 16
10 ! 6 " 16
Plus 10 Combinations
4 ! 10 " 14
10 ! 4 " 14
seventeen
17
Math Words and Ideas
Addition Combinations
(page 3 of 4)
Here are some more categories to help you learn
more of the addition combinations.
Near-Doubles Combinations
Some combinations are close to a doubles combination you
know. Here are two examples.
Doubles minus 1
6!7#
7!6#
Doubles plus 1
7!8#
8!7#
Think: 7 ! 7 " 1
Think: 7 ! 7 ! 1
!1
"1
7 ! 6 # (7 ! 7) " 1 # 13
7 ! 8 # (7 ! 7) ! 1 # 15
Plus 9 Combinations
You can learn some combinations by relating them to a
plus 10 combination you know. Here are two examples.
5!9#
9!5#
Think: 9 ! 1 ! 4
Think: 10 ! 5 " 1
"1
9 ! 5 # 10 ! 4 # 14
18 eighteen
9 ! 5 # (10 ! 5 ) " 1 # 14
Math Words and Ideas
Addition Combinations
(page 4 of 4)
As you practice all the addition combinations, there will
be some that you “just know” and others that you are
“working on.” To practice combinations that are difficult
for you to remember, think of a combination that you know
as a clue to help you.
Here are some examples. Gil and Ines have different clues
to help them solve 5 ! 7.
Gil:
I think of 7 ! 7,
and then subtract 2.
5
7
!
!
"
"
7
5
Clue: 7 + 7 - 2
Ines: First I add 5 ! 5,
and then add 2 more.
5
7
!
!
7
5
"
"
Clue: 5 + 5 + 2
Do you know these combinations or are you learning them?
5
8
7
!7
!6
!4
nineteen
19