Setting up Word Problems

SETTING UP WORD PROBLEMS

1) Read the problem all the way through to the end. 2) Draw a picture when useful, appropriate, or possible. 3) Determine what you are supposed to find. Write it down EXACTLY. Example: If the problem tells you to find how much money was invested at each interest rate, then you MUST write… “The amount invested at 10% =T” & “The amount invested at 12% = V” Do not write T = 10% or V = 12% T and V represent unknown amounts of money, not given (known) percents. 4) Choose a variable (as defined below) to represent what you are to find. 5) Whatever you identified in number 3 needs to be called something. Designate variables to represent UNKNOWN VALUES. 6) Read the problem again 7) Organize your information to make sense for the situation given in the problem. 8) Set up equations showing relationships between values. 9) Solve the problem using the equations making sure to answer all questions asked.

WHAT IS A VARIABLE?

A variable is a symbol that represents an unknown number. A variable is NOT DEFINED AS a letter or as any specific letter of the alphabet, but as a symbol that represents an unknown quantity or number.

Example: When needing to represent the population of China—do not say c = China, say c = population of China (the NUMBER of people in China).

When you calculate c, you find the NUMBER of people in China. You do not find China.

Example: When needing to represent the height of a tree—do not say t = tree, say t = height of tree (the NUMBER of feet, meters, etc in the height of the tree).

When you calculate t, you find the NUMBER of units in the height of the tree. You do not find the tree.