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 […]

# Tag Archives: Mental Math

# 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 […]

# Find the LCM – FAST!

Here’s a short video on how to find the LCM. It uses a trick that I have not seen anywhere else, and the approach is quite fast. The information in this video dovetails with the info in this post. I hope that you find this video helpful.

# Find the LCM (aka LCD) in Two Easy Steps

Here’s a quick way to find the Least Common Multiple for a pair of numbers. It involves two short, quick steps: reducing a fraction. Then flipping it and multiplying.

# Find the LCM in a way that makes sense! (Part 2)

Two little exceptions to the technique laid out in yesterday’s post. To make sure you don’t overlook the exceptions, read this post today.

# Find the LCM in a way that makes sense! (Part 1)

For the most part, when you set out to find the least common multiple for a pair of numbers, you are asked to go through a bunch of steps that don’t really make sense. Till now! Here’s a way to find the LCM that truly does make sense. This post explains it in clear English, […]

# (Divisibility) Practice Makes Perfect

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

# How to Find the LCM – FAST!!!

Quick way to find the LCM for any pair of numbers.

# “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!