Math Word Problems Demystified - A Self Teaching Guide

Guess and Test

This strategy is similar to the previous one except you do not need to make a

list. You simply take an educated guess at the solution and then try it out to

see if it is correct.

EXAMPLE:The sum of the digits of a two-digit number is 11. If the digits

are reversed, the new number is nine less than the original number.

SOLUTION:

GOAL: You are being asked to find a two-digit number.

STRATEGY: You can use the guess and test strategy. First guess some

two-digit numbers such that the sum of the digits is 11. For example, 83, 74,

65, etc., meet this part of the solution. Then see if they meet the other

condition of the problem.

IMPLEMENTATION:

Guess: 83; reverse the digits: 38; subtract: 83
 38 ¼ 45

Guess: 74; reverse the digits: 47; subtract: 74
 47 ¼ 27

Guess: 65; reverse the digits: 56; subtract: 65
 56 ¼ 9

The number is 65.

EVALUATION: The sum of the digits is 6þ 5 ¼11, and the difference is

65 
 56 ¼9.

EXAMPLE:Each letter represents a digit from 0 through 9. Find the value

of each letter so that the following is true:

x

x

þx

wx

258 LESSON 21 Using Other Strategies