The Calculator Dilemma: How Relying Too Much Can Hurt Your Math Skills

Calculators can help with routine arithmetic involving large numbers, but students should not rely on them. I often see a number of bad habits creep into students’ math abilities that I blame on calculators:

• 96357.325 x 1 is equal to 96357.325 and 94567.234 x 0 is 0. You don’t need a calculator to tell you those answers.

• (1/3) x 6 is equal to 2. Some calculators will tell you it is 1.99999999 because of internal representation of numbers in chips.

• -2² is equal to -4 and is different than (-2)² = 4. Calculators are very bad at order of operations, the BEDMAS rules (brackets, exponents, division and multiplication, addition and subtraction) that are crucial for math communications.

• I find that students who type a long calculation into their machine and then hit “=” (aka “chaining a calculation”) are destined for disappointment. Better to break down the calculation into smaller parts, calculate them separately, write down the intermediate results, then combine those.

• Try (2 – 10/10x4) 3 /(3*(2-4/2) +1). Did you get -6? No? I blame your calculator.