Don't just have kids memorize facts. Help them learn and understand the mathematical principles! Teach basic ''Math Families'' with the 4-Step Method! Students learn one math fact to know and understand four! Motivates students as they realize there are fewer and fewer facts to learn! The Math Fact Cards are color-coded to reinforce the commutative properties of addition and the inverse operation of subtraction! 144 Addition cards and 144 Subtraction cards with a reproducible Resource Guide. Facts include tables 1-12. Each card measures a large 5 1/2'' X 2 1/8'' and has a plastic-coated wipe-off surface!