I wonder if presenting arithmetic problems as simple algebra problems helps students in a real algebra course later on.
This seems to be a trend in many math programs today, I believe for several reasons:
1. It encourages thinking about arithmetic operations in terms of parts to a whole, as well as in relation to inverse operations, which can have a helpful effect on cementing memorization of math facts as well.
2. It predisposes children not to fear variables and equations.
3. It impresses people, including many parents, when young children can "do algebra". I've seen some parents bragging on the basis of these types of problems.
I don't know how much the first two translate to increased ability when learning algebra later on, but I think lack of fear is probably helpful.
