Math Facts

Here are some of the strategies  for learning the addition facts:

1. Adding zero: The sum is always the other number.  8 + 0 = 8, 0 + 4 = 4
2. Counting on by 1 or 2: Find sums like 5 + 1 or 6 + 2 by simply counting on.
3. Combinations to 5: Learn combinations to 5 such as 3 + 2 or 4 + 1
4. Combinations to 10: Learn combinations to 10 such as 6 + 4 or 8 + 2
5. Doubles: Learn sums of doubles such as 4 + 4 or 6 + 6
6. Nines: When adding nines, the one digit in the sum is always one less than the number added to nine.  For example 7 + 9 = 16, the 6 is one less than 7.                           Another example, 5 + 9 = 14
7. Doubles plus one: When addends are consecutive numbers, count on from the double.    For instance, 7 + 8 becomes 7 + 7 + 1.  Another example, 8 + 9 becomes 8 + 8 + 1
8. Sharing doubles: This method works when the addends differ by two.  When this occurs, it is possible to subtract 1 from one addend and add to the other addend.  This results in a doubles fact that has already been memorized, 7 + 5 becomes 6 + 6.  Another example, 6 + 8 becomes 7 + 7. 
9. Commutativity: By changing the order, 3 + 4 to 4 + 3, facts can be recalled.

It is expected that students respond automatically when asked an addition fact.

Helping your child with subtraction:

Here are thinking strategies for learning the subtraction facts:

1. Fact Families: This strategy works when students understand the relationship between addition and subtraction.  When students see   6 - 2 and think 2 + ? = 6
2. Counting backwards: This method is similar to counting on in addition.  It isn't quite as easy.  Students should only count back up to three.
3. Zeros: The pattern for subtracting zero is readily recognizable.  5 - 0 = 5
4. Sames: This method is used when a number is subtracted from itself; this is another generalization that students can quickly identify.   7 - 7 = 0

Using cards to reinforce basic facts:

Addition 21: Sort the decks into two piles, red and black.  Set the red decks aside.  The cards are divided between the players.  Each player turns over two cards and adds the values together.  Whichever player has the highest sum wins the hand.  To begin with, use only the number cards and as students become more proficient, add the face cards assigning values for each.

Subtraction 21: The cards are divided between the players.  Each player turns over two cards and adds the values together if both cards are black or red.  If a player turns over a black and a red, he/she must subtract the values.  Whichever player has the highest or lowest answer wins the hand.  With older students who understand integer addition/subtraction rules, this game can become very challenging.  To begin with, use only the number cards and as students become more proficient, add the face cards assigning values for each.

Below are links for practice: