It's not a very hard task to translate english into math. It just requires practice. Let's take this problem for example:

When a certain tree was first planted, it was 4 feet tall, and the height of the tree increased by a constant amount each year for the next 6 years. At the end of the 6th year, the tree was 1/5 taller than it was at the end of the 4th year. By how many feet did the height of the tree increase each year?

A. 3/10
B. 2/5
C. 1/2
D. 2/3
E. 6/5

So we are told that the initial height of the tree was 4 feet and that its height increased by a constant amount each year for the next 6 years. Let's call the constant amount x.

Now, at the end of the 6th year, the tree will be 4+x+x+x+x+x+x=4+6x feet tall and at the end of its 4th year, the tree will be 4+4x feet tall. We are told that 4+6x is 1/5 greater than 4+4x, so let's form an equation from the given info.

4+6x=(1+1/5)(4+4x)

4+6x=6/5(4+4x)

4+6x=24/5+24x/5

x=2/3.

So, the height of the tree increased by a constant amount of 2/3 feet each year.

Take each word problem similar to this one step by step, and be sure to read the problem carefully.

Thanks truplayer256. I was looking for catch phrases or any other techniques one might refer to when it comes to define an equation.