Math Word Problems Demystified - A Self Teaching Guide

EXAMPLE:Tina spent $1.00 for parking and one-half of the remainder of

her money in a department store. Then she spent $3.00 for lunch. Arriving

back home, she found that she had $7.00 left. How much did she take to

the store?

SOLUTION:

GOAL: You are being asked to find how much money Tina had before going

shopping.

STRATEGY: Work backwards.

IMPLEMENTATION: Work forward first and then work backwards.

1. Spent: $1.00 on parking. Subtract $1.00.


2. Spent^12 of the remainder in the department store. Divide by 2.


3. Spent $3.00 on lunch. Subtract $3.00.


4. Has $7.00 left.
   Reversing the process:


5. $7.00


6. Add $3.00 $7.00þ$3.00¼$10.00


7. Multiply by 2 $10.00 2 ¼$20.00


8. Add $1.00 $20.00þ$1.00¼$21.00
   Hence, she started out with $21.00.
   Many times there is no single best strategy to solve a problem. You should
   remember that problems can be solved using different methods or a
   combination of methods.

Try These

Use one or more of the strategies shown in the lesson to solve each problem.

1. How many cuts are needed to cut a log into 5 pieces?

264 LESSON 21 Using Other Strategies