Encourage your child to use the following
strategies to help learn and understand their addition facts.
Counting all
This strategy is most effective with very young
learners (PreK-K). It is very straightforward and is part of the scaffolding
that children need in order to use other strategies efficiently. For example,
to solve 4+5=9, the student gets 4 of something and 5 of something and counts
how many there are altogether.
Counting on
This strategy is taught directly in grade one. To
solve 5+3=, the students counts on "6, 7, 8." While this is being taught,
children are also directed to start with the higher number and count on from
there. To solve 3+5=, the student would still start at 5 and count on "6,7,8."
Doubles
Facts such as 3+3=6 are easier to remember than
facts with two different addends. If a child seems to utilize the doubles
strategy, then they may benefit from the doubles +1 strategy or the near
doubles strategy. If they know that 3+3=6 then 3+4 would equal one more.
Making a Ten
Facts with a sum of 10, such as 2+8 and 6+4, are
also easier to remember than other facts.
Using a Ten
Students who are comfortable partitioning numbers
and combining small numbers can use that knowledge to find the sums of larger
numbers. There are many strategies that involve using the number ten. For
example, to find 9+4, we can partition the 4 into 1+3 and then 9+4=9+1+3.
Encourage your child to use the following
strategies to help learn and understand their subtraction facts.
Using a Ten
Students follow the pattern they find when
subtracting ten, i.e 17-10=7 and 13-10=3, to learn "close facts," i.e. 17-9=8
and 13-9=4. Since 17-9 will be one more than 17-10, they can reason that the
answer will be 7+1 or 8. Ten is a part in the part-part-whole scenario.
Thinking Addition
To find the answer to 15-8, a student thinks, "8
plus what number equals 15? Since 8+7=15, 15-8=7."
Making a Ten
Children are often comfortable with the sums of ten,
i.e. 6+4=10 and can use them to find differences from ten, i.e. 10-6=4 and
10-4=6.
Using Doubles
If students are comfortable with doubles, i.e.
8+8=16 and 6+6=12, they can use these facts to learn "half-doubles" as well:
16-8=8 and 12-6=6. These facts can then be used to figure out close facts (or
near doubles) such as 13-6=7 and 15-8=7.
Counting Strategies
Students may use counting strategies, such as
counting up or counting down. Counting up is most efficient with the numbers
are close together, as in 11-8 or 30-28. To subtract 8 from 11, students start
at the lower number (8) and keep track of how many they count to get to 11 (9,
10, 11). Counting down is most efficient when the number to be subtracted is
small, as in 11-3 or 30-2. In this cse, students start at the higher number
(11), count backward the amount of the lower number (3) and find the number he
stops at (8).
All strategies are directly from MTB Kendall/Hunt Publishing
Company