Subtraction Strategies
Addition and subtraction are two of the most basic math skills which
are important to master. Oftentimes, completing an addition algorithm
is somewhat simple students to accomplish. Simple subtraction
algorithms may be easy as well. However, when a student is asked to
regroup or borrow in a subtraction problem, things can get a little
tricky.
Subtraction Algorithm
GOOD STRATEGIES TO USE!!
Number Line
Number lines for subtraction problems are a bit different than those for
addition problems. I encourage my students to try using number lines
to subtract because they are easy to create on tests in which students
cannot use 100 charts or other manipulatives. To subtract on a number
line, students put the lower number at the start of their number line
and the larger number at the other end. Then, students jump from one
number to the other. In the end, they add up their jumps to arrive at
their answer.
Chunking
We have not done a lot of work with chunking to subtract, however it
can be done. Students will pull apart their number just like they do in
addition. However, this time they will subtract the parts instead of
adding them together. **I do not recommend that students use this
strategy on problems that require regrouping or borrowing.
Hundreds Chart
Subtracting on a hundreds chart is a great place for students to start. It
provides a concrete group of numbers for students to count and
manipulate. Students should first subtract their tens by going up the
rows. Then, students should count backwards by ones to finish their
problem.
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