As you teach mental algebra to your child, the first step is to work on problems that cover situations with people or objects that are equal distances away from each other, or an equal number of fruits were purchased, or the stick was broken in the middle.
After you get your kids through the problems that focus on “one independent unknown with one independent equation” type, it is time to get more complex.
Now you teach your child how to solve the problems where things are not equally divided. It isn’t hard, as you might imagine, just different. And so you teach her to figure out the quantities of two items when they are not the same but are related by some constant (like one being twice the other or one being three less than the other…)
This is where it becomes helpful to think in terms of x’s, but the problems can still be generally done in your (or your child’s head). For those of you who remember algebra class, this is the “if you have two independent unknowns, you need two independent equations to solve for the unknowns” maxim at work.
So now you are probably asking, “Why am I teaching this mental algebra stuff to my kid when I never learned this in school and I turned out just fine?” The answer is that this is the algebra that Ben Franklin and George Washington and a whole pile of really, really smart blokes learned and don’t you want to give as much opportunity to your child as you can? And it is also really good mental exercise, and gives him concentration practice, and a whole bucket-full of self-confidence.
For algebra lessons like these, see www.TeachMeBetter.org – I put up a new page as we finish up the editing process on the curriculum that we will be publishing soon.