Archive | Mental Math

“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!

Multiplication Trick #3 — Multiply by 25 FAST!

Here’s a great way to help students get two for the price of one. First, they make connections between multiplication and a topic very dear to their hearts: money. That’s because the trick is for multiplying by 25, and in using this trick, you use the fact that four quarters make a dollar. Secondly, students […]

Fraction divided by a fraction

Is there any way to make it easier to divide one fraction by another fraction? Read the post and you’ll see that it is possible. Here is a great math trick that makes it easier to divide fractions. Read the post and then try the division trick. You’ll be glad that you did.