Long division as repeated or continued subtraction
Learn the continued subtraction algorithm for division (aka chunking), by using the example of bagging apples. My first example is to bag 771 apples in bags of 3. Subtracting three apples at a time (and keeping a count of the bags used) would be slow, so instead, we subtract 300 apples (which go to 100 bags) at once. The number of bags then is the answer to the original division problem (the quotient).
I refine the algorithm yet a bit more, until we arrive to the one that exactly matches the steps in long division! The last example shows a comparison where I solve the same problem BOTH with continued (repeated) subtraction and long division.
This lesson is meant for about 5th grade math; whenever students are learning about long division and why it works.
See also
Problem solving with bar models: fractional part of a whole — video lesson
Math Mammoth Grade 5 curriculum
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