In our math pattern unit we have been working a lot on variables. A variable is either a constantly changing number, as is the case in the first picture below, or the variable can be the unknown that we are trying to find, as in the next two pictures. We are learning how to figure out x + 15 = 35, for example. What seems to confuse students most is when it is written a different way 35= x + 15. It means the same, but they get thrown off by the equal sign at the front of the equation.
I have been trying to help them remember that the letter or variable stands for "something." So in the above question, something plus 15 equals 35, so how are we going to find out what that is. The tricky part is it is not always the opposite operation. In the above example, they need to subtract the two numbers they have to find the unknown, whereas in a question like 35= 41 - x, they are not doing addition with the numbers, they still have to subtract. We are slowly working through figuring out what to do when!
I have been trying to help them remember that the letter or variable stands for "something." So in the above question, something plus 15 equals 35, so how are we going to find out what that is. The tricky part is it is not always the opposite operation. In the above example, they need to subtract the two numbers they have to find the unknown, whereas in a question like 35= 41 - x, they are not doing addition with the numbers, they still have to subtract. We are slowly working through figuring out what to do when!