Mental Math Mastery
for Classrooms and Homes

Multiply any two-digit number by 11 — in your head, in seconds.

Square any number ending in 5 by multiplying and appending 25.

Add the tens first, then the units — the natural mental order.

Round and recover. Turn ugly subtractions into easy additions.

Split the tens and units, multiply separately, then add.

Round to the nearest ten, multiply, correct by one square.

Master 2-by-2 multiplication using factoring, addition, and subtraction methods.

Learn left-to-right division and the Rule of Thumb memory technique.

Use simple algebra to read minds and force specific answers.

Cast out nines to uncover hidden numbers in massive calculations.

Predict the sum of 10 numbers before they're all written down.

Any number > 34 becomes a magic square in seconds.