Tag Archives: Mental Math

GCF of 2 Numbers, Trick Finds it Fast

Ever need to find the GCF of two numbers? Here’s a trick for finding the GCF of any two numbers — very quickly. This is an original trick, so I doubt you’ll find it anywhere else online. But most important, it’s easy to use, and it works no matter how large the numbers might be. Also nice … learning this […]

PSAT Math Test, Day of Reckoning … ?

It has finally happened … students have taken the new PSAT. I know because Singing Turtle Tutoring (the tutoring company that my wife and I run) prepares students for this test, and over the last two weeks I’ve been helping many get ready for the new PSAT’s  math section. My big word of advice for many students:  learn […]

(Divisibility) Practice Makes Perfect

Practice problems for reducing fractions. Use divisibility tricks to reduce fractions.

“Fraction Sandwich” Practice Problems: Dividing a Fraction by a Fraction (without choking!)

Last week I sent out a blog that helps students divide a fraction by a fraction. The technique is called the “Fraction Sandwich.” To help students “get the hang” of this technique, here are 10 practice problems for dividing one fraction by another.

Multiplication Trick #5 — Multiply Two-Digit Numbers by 11

There’s a quick and easy trick for multiplying two-digit numbers by 11. Dazzle your friends, amaze your family, begin your career in show-biz … o.k., maybe not show-biz, but still this is a pretty cool trick. Check it out!