A Method of Front-End Arithmetic
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Eddie Newton Carver Area High School
l3l00 S. Doty Avenue
Chicago IL 60627
Upon completion of the Front-End Mathematics lesson, students will be able
a. Transfer computational fatigue from the most significant to the
least significant columns.
b. Eliminate carry-overs and their errors.
c. Use one or more of the fundamental laws of commutation, association and
distribution, and the concepts of place value and regrouping.
Many peoples contributed to the development of the modern system of
numerals. Any society that uses Arabic numerals can use the Front-End Method of
Arithmetic for calculating.
Notebook Paper for a class of 20 students.
Pencils for the class.
Twenty store receipts from supermarkets.
Students will be given four shopping lists and asked to estimate the
number of $20 bills needed to purchase the items on each list. Calculators are
Students will be asked to add the figures on the list to obtain the exact
Students will be taught the Front-End Method of Arithmetic.
Students will recalculate the shopping lists using front-end arithmetic
Example of front-end addition:
The numbers are lined up as usual in their proper vertical columns. The
first column is totalled and the subtotal, 3+6+9=18, written in its proper
place under the line. At this stage we already know that the final sum will
exceed $l80. The second column is summed, its subtotal, 7+3+7+8=25, is written
in its proper place under the line. The first two subtotals add up to $205, a
second approximation to the final answer. The third column subtotal, 24, is
again written in its proper place under the line. The first three subtotals
give the partial sum $207.4, a third approximation to the final answer. The
fourth column subtotal, 22, is again written in its proper place under the line.
Added to the previous partial sum, it yields the final answer $207.62.
Students will be given a post-test consisting of ten front-end addition
problems using supermarket receipts. Students will be expected to use this new
method to compute the problems with l00% accuracy.
Front-end arithmetic provides an interesting variation for and supplement
to, the classical rear-end approach. Students are able to add columns of
figures without carrying. This method has real-world application to consumer
DeBethune, Andre J. A Method of Front-End Arithmetic, in Enrichment
for the Grades, The National Council of Teachers of Mathematics, Inc.
Washington, D.C., l963.