Strategies For Solving Addition Facts
Count on 1, 2 or 3 times
You say the bigger number and count on 1, 2 or 3
times.
5+1=6
7+2=9
4+3= 7
Doubles facts
We use pictures to help us solve these facts.
2+2=4
1+1=2
(2 legs in front and 2 in back)
3+3=6
(a six pack)
4+4=8
(4 legs on each side)
5 + 5 = 10
6+6=12
(12 eggs in a dozen)
7+7=14
(2 weeks is 14 days)
8+8=16
FAST TEN
These are quick and easy facts to solve.
10+5=
Put the 5 in the hole and it makes it 15.
10+3= 13
Put the 3 in the hole and it makes 13.
NAUGHTY NINE
The 9 is a naughty number!
He steals!
9+4=
He steals 1 from the 4 and makes him a 3.
Then, the 9 becomes a 10 + the 3 left over.
10+3= 13 so 9+4=13
9+5 =
He steals 1 from the 5 and makes it a 4.
Then the 9 becomes a 10 + 4 left over.
10+4= 14 so 9+5 = 14
(2 spiders make me "SICK”-sixteen)
9 + 9 = 18
DOUBLES +1 FACTS
Doubles + 1 facts are made of numbers that are
next door neighbors on the number line.
Examples:
5+6=
4+3=
7+8=
You find the baby number and double it.
5+6=
5 is the baby so double it 5+5=
Then, give it a birthday.
He was 10, now he is 11.
So, 5+6=11
7+8=
7 is the baby number so double it 7+7=
Then, give it a birthday.
He was 14, now he is 15.
So 7+8=15
HUNGRY EIGHT
The 8 is a hungry number!
He eats 2 from the other number!
8+6=
He eats 2 from the 6 and makes him a 4.
So then he becomes a ten, 10+ the left over 4.
10+4=14 so 8+6=14
8+7=
He eats 2 from the 7 and makes him a 5.
So then he becomes a ten, 10+ the left over 5.
10+5=15 so 8+7= 15
Strategies For Solving Subtraction Problems
The Zero Rule
Any number minus 0, the answer is the other
number.
8-0=8
6-0=6
Count back 1, 2 or 3 times
If a problem has a -1, say the bigger number and
count back 1 time.
9-1=8
If a problem has a -2, say the bigger number and
count back 2 times.
8-2=6
If a problem has a -3, say the bigger number and
count back 3 times.
Subtract All
Any number minus itself is 0.
9-9=0
5-5=0
100-100=0
Backwards Doubles
Use the doubles facts and turn them around...
If 5+5=10, then 10-5=5
If 6+6 =12, then 12-6 =6
10-3=7
Using the number 9 to subtract...
Using the number 8 to subtract...
Naughty Nine is sorry for stealing!
Hungry Eight is giving back!
12-9=
The 9 was naughty and stole one.
Now he gives the one back to the number 2.
2+1=3
So, 12-9=3
14-8=
The 8 was hungry and took two.
Now he gives the two back to the number 4.
2+4=6
So, 14-8=6
13-9=
Naughty 9 gives one back to
the number 3.
3+1=4
So, 13-9=4
17-8=
Hungry 8 gives back to the
number 7.
7+2=9
So, 17-8=9