Conventional wisdom says that parents can use flash cards or competition to help children memorize their math facts. But there are additional ways to reinforce math fluency in daily life.
Here’s how I do it. A child is playing a math computer game or working a homework exercise. Child: “Mom, what’s 8x4?”
I could just give them the answer, or I could tell them to figure it out themselves. Alternatively, I choose to activate their mental math by questioning them about a related fact they already know.
Child: “What’s 8x4?”
Mom: “What’s 10x4?”
Mom: “Can you use 10x4 to figure out 8x4? How many 4’s would you have to take off of ten sets of four to get eight sets of four?”
Child: “Um, 2 sets”
Mom: “So what’s 8x4?”
Child: “40-8,” so 32.
Basically, you have guided them to think of 8 as 10-2. Taking 4 x 8 is the same as 4 x (10-2). Then mentally, they can take (4x10) - (4x2) = 40-8 = 32. Instead of breaking 4x8 up this way, you could also have broken it up as 8x(5-1) = 40-8 = 32. Or, 4x (4x2) = (4x4)x2 = 16x2 = 32.
Likewise, children can break up division problems into something they already know. 32/8=4 can be thought of as (16+16)/8. Then make two divisions, 16/8 + 16/8 which gives 2+2, or 4.
When children have an underlying mental structure of why 4x8=32, it’s easier for them to remember it. Later on in the day, I would keep asking questions that would utilize 4x8=32. For example, “If I want to buy 8 strawberry shakes at $4 each, how much would the total be?” Also, directly ask them to recall 4x8=32 and 8x4=32 so they will have it memorized.
When helping children learn their basic facts, focus on fluency. “Computational fluency refers to having efficient and accurate methods for computing. Students exhibit computational fluency when they demonstrate flexibility in the computational methods they choose,understand and can explain these methods, and produce accurate answers efficiently.” (NCTM, 2000, p. 152). When fluency undergirds math facts, memorization follows.
National Council of Teachers of Mathematics (NCTM). Principles and Standards for School
Mathematics. (2000). Reston, VA: NCTM.