Put Down That Calculator!

Most parents fret today over their child’s use of digital devices. They fear that social media, iPods, Xbox 360, or smartphones are taking over children’s collective brains and lives.{{more}} Well think again. The most harmful device your child uses today might very well be their handheld calculator.

Many classrooms from 6th grade and up allow calculators to be used. Calculators are particularly helpful with upper level math problems such as graphing parabolas and such. But, in many instances, they become overused.

Calculators are being used to do basic arithmetic operations. Instead of mental recall of multiplication tables, or manual execution of long division, or multi-digit multiplication, it is far easier to get out the handheld calculator.

For many students, calculator overuse is responsible for atrophied mental math skills. These waning skills, if left uncorrected, will lead to problems not only in their next grade level, but beyond that in executing life’s daily challenges. Most experts would argue that calculators should be a tool used to speed up computations that a student already knows how to perform manually or mentally.

Some of you might immediately discount the ability to do mental math and manual calculations as unnecessary or dismiss it as “old school.” You might be tempted to use a false parallel to today’s spell-check. In other words, why bother to learn to spell if the computer will automatically correct your spelling for you. By that logic, why even learn the definition of words if we could look each one up in a dictionary. For that matter, why learn about the Civil War if you can just copy and paste information about the war from millions of websites.

Mathematicians have always searched for efficient ways to perform mundane calculations to free their minds to focus on more complex problems. The abacus and slide rule are two such examples. Thus, the real question is not “if” to use a calculator, but “when.” When is the appropriate time to introduce a calculator so that it does not become a crutch, an enabler, but rather is used to extend a child’s knowledge and ability.

There are many opinions, both pro and con, as to when it is OK to allow a child to use a calculator. With all the divergent points of view, what’s a parent to do? Here is a simple test

If your child is currently using a calculator in class (e.g. 6th grade and up), give them this 10-question test below. They should be able to answer each in their head within about two seconds:

• 9 times 7 (63)

• 17 minus 9 (8)

• 68 plus 15 (83)

• 72 divided by 8 (9)

• 80 times 3 (240)

• 51 minus 14 (37)

• 7 times 8 (56)

• 24 divided by 3 (8)

• 8 plus 7 (15)

• 150 divided by 25 (6)

If they can do the above exercises in their head, you can feel pretty confident they are not using a calculator in class as a crutch. Children that can do these in their heads will be using the calculator, as it was designed; to save time, to allow for more complex operations to be thought through.­­

If your child cannot answer the above questions with relative ease, don’t worry so much about their facebook, smartphone and texting usage … worry instead about their overuse of calculators.

Mark Ahrens is Center Director of Mathnasium, a math-only learning center. He can be reached at 203-783-1490 or milford@mathnasium.com.