Teach Your Kids Arithmetic - The Quick-Add - Part I
In continuation of my series on arithmetic, I present here a
topic that was one of the cornerstones in my book "Arithmetic
Magic." To fully understand how this concept aids one in
arithmetic operations, we need to lay some foundational ideas
first. The "Quick-Add" is an enormously valuable tool to help
children master quick arithmetic, particularly applied to
summing numbers. Today the calculator has crippled even the
ablest students. Hardly a one knows his fundamental
multiplication facts, as the omnipresent calculator does this
operation for him. This situation is understandable, and a
comparison I can make is one regarding remembering telephone
numbers. Since the ubiquitous cell phones store numbers, I no
longer memorize people's numbers as I have no need to.
Analogously, students no longer can add or multiply because the
calculator does it for them. This is a problem for the following
reasons: 1) not mastering arithmetic leads to problems in
mathematics down the road; 2) not being able to add or multiply
engenders frustration when doing basic homework assignments; and
3) lack of doing = future lack of doing, which further increases
the chance of mathematical illiteracy.
The Quick-Add method gives students a viable alternative to
performing quick sums without the aid of calculators or pencil
and paper. This method is based on the idea of "complements."
The word "complement" means "to complete," and this is exactly
what these numbers do. A "10-Complement" completes the 10; a
"100-Complement" completes the 100, and so on. Why this idea is
so useful is that it aligns itself with the simplicity inherent
in the metric system, in which all units and measurements are
based on the number 10 and its multiples. To begin to understand
this idea, let me present the following scenario: If I said to a
child, "What is 8 + 9?", and wanted a fast answer, the child
would probably start and stumble, resorting to counting on his
fingers or trying feverishly to reckon the sum. Granted, there
are those children who are quick with this type of thing and,
rather fast, can come up with the answer of 17. My focus,
however, is not on these children. The healthy have no need of a
doctor. My focus is on the children who struggle with basic
arithmetic operations and experience tremendous frustration:
which when germinated, leads to negative attitudes toward
mathematics and ultimately crystallizes into self-doubt, fear,
and dread of this most wonderful subject. The consequences are
truly disastrous as many students I have worked with
realize--after I healed them of their mathematical ills--that
they were actually good at math. Imagine what better problem
solvers we would be in general if we had math on our side rather
than against us!
Let's return to the idea of complements. In the 8 + 9 example,
we see the sum is 17. How much faster would a child come up with
the answer 17, if I said "What is 10 + 7?" Now the careful
analysis of the difference between 8 + 9 and 10 + 7 reveals some
very interesting things, and shows how the circuitry of the
brain capitalizes on some very important mathematical facts. Let
us examine these. It is indeed true that 0 and 1 are two very
special numbers, but for addition, 0 is the number whose special
property applies here. The number 0 has the "Additive Identity
Property." This simply means that 0 plus any other number yields
the given number. That is 0 + 5 = 5; 0 + 4 = 4, etc.(From an
addition perspective, I guess one could say that 1 is special in
that adding 1 to any number is quite intuitive as we are only
incrementing said number one unit: thus 8 + 1 = 9--you get the
idea.)
Now complements of a number are those numbers, which when added
to the given number, yield a sum of 10. For example, the
10-complement of 8 is 2, since 8 + 2 = 10. The 10-complement of
3 is 7, since 3 + 7 = 10. How we tie the concept of complements
to the Quick-Add is as follows: in analyzing 10 + 7, we rewrite
this example as 10 + 07. We insert a 0 in front of the 7 as a
placeholder for the empty "tens column," and to bring the
numbers into parallel structure. Now let us examine how the
brain circuitry works in doing 10 + 07. The brain performs 1 + 0
in the "tens column" and 0 + 7 in the "ones column," thus
capitalizing on the "Additive Identity Property" of 0. This is
in fact a "no-brainer." Therefore, our strategy tool for
addition will be to convert addition problems into their
associated "Quick-Adds." Once done, this simplifies additions
enormously.
Stay tuned, as in Part II I will go into much more detail about
this whole procedure.