Divisibility Rules poster and why do we need to know our numbers

In my work with high-school students I’ve noticed that often students struggle with Algebra not because they can’t understand the concepts, but because they have difficulties with Arithmetic. They get so frustrated with the calculations they have to do, they don’t have the patience or the time to work through the problems.

Math is a complex science, but no matter how complex the concepts are they are all built on simple blocks – numbers. To be effective in Math, we need to understand how numbers interact with each other. I often hear students say “Why do I need to be able to calculate when I have a calculator!” I agree that if we have such a useful tool, it doesn’t make sense to do calculations by hand. However that doesn’t negate the need to know our tables and other number facts. Very often we get a hint for a solution…