 # Addition Fact Strategies

## Count Ons Turn-Arounds Zero Facts

Count-ons facts are numbers 0 - 9 that only add +1, +2, +3.  When practicing count-ons start with the largest number and count up.  For example: 5+3.  Say 5 and then count-on 6,7,8.

Turn-around facts are those facts in which the numbers are just turned around.  For example 5+3=8  and 3+5=8

There are 19 zero facts and their turn-arounds.  A zero in an addtion fact makes no change.  The sum is the same as the number given.  For example  8+0= 8.

## Double Facts

Doubles facts are directly related to knowing the doubles addition facts. If you know 9 + 9 = 18, then you know 18 – 9 = 9.  Students are recognizing these fact families (we have also practiced them using fact triangles)

## Double Facts Song

one plus one is two

two plus two is four

…listen to me, I know more!

three plus three is six

four plus four is eight

…to hear more you are going to have to wait!

five plus five is ten

six plus six is twelve

seven plus seven is fourteen

…this should be on a movie screen!

eight plus eight is sixteen

nine plus nine is eighteen

...now you know the routine!

## Count Ups

There are 15 count-up facts.

Count-ups are any fact where the answer numbers in the fact are 1, 2 or 3 apart.  When practicing count-ups, start with the smallest number and count up.

For example:  9-7, start with 7….say 8, 9 (counting up 2) so your answer is 2

## 10 Frame Facts

10-frame facts are facts that are built on a 2x5 grid.  Have your child fill the grid with 10 objects.  Then, remove one or more objects to create a 10-frame fact.

To show 10 - 4, start with 10 objects….remove 4, your child will see that 6 are left.  Showing, 10 - 4 = 6.

## Magic 9s

Magic -9’s use number patterns.  One pattern is….the answer is one more than ones place of the digit begin subtracted.  For example, 14 – 9, 5 is one more than the 4 in the ones place in 14, making the answer 5.  Another pattern is…..adding the digits of the number being subtracted.  For example, 14 – 9, 1+ 4 = 5.  These patterns only work for the magic 9’s.

## Sharing Facts or Jump in the Middle and Double

There are six Sharing Facts (and their turn-arounds).  This strategy is used when the numbers being added are separated by 1 number such as 4 and 6.  The larger numeral will ‘share’ 1 with the smaller numeral so they are equal, thus creating a “Double fact”.

Example:  4 + 6; ….6 shares with 4 making the fact 5 + 5.

5 + 5 = 10, therefore 4 + 6 = 10

Another strategy for these types of facts is Jump in the Middle and double.

Let’s take 5 + 7.  The missing middle number is 6. (5, 6, 7)  The strategy is to double the missing number. (6+6=12 so 5+7=12)

Example:  6+8  Think 6,7,8.  Then think 7+7=14, so 6+8=14.  