Math Word Problems Demystified - A Self Teaching Guide

Notice the relationship between the day and the total amount earned: 1^2 ¼1,

22 ¼4, 3^2 ¼9, 4^2 ¼16, 5^2 ¼25. Hence for 30 days’ work, the employee would

earn 30^2 or 900 dollars.

EVALUATION: You could check your answer by adding the first 30 odd

numbers.

EXAMPLE:Find the sum of the digits for the answer to (111,111,111)^2.

SOLUTION:

GOAL: You are being asked to find the sum of the digits of the given number

squared.

STRATEGY: Make a table starting with 1^2 ,11^2 , 111^2 , etc. Find the sum of

the digits and see if there is a pattern.

IMPLEMENTATION:

Number Number squared Sum of digits

12 11

112 121 4

1112 12321 9

11112 1234321 16

111112 123454321 25

The pattern is similar to the one shown in the previous problem. If there are

9 digits in the number, the sum of the digits should be 9^2 ¼81.

EVALUATION: You could square the number and sum the digits.

Solve a Simpler Problem

To use this strategy, you should simplify the problem or make up a shorter,

similar problem and figure out how to solve it. Then use the same strategy to

solve the given problem.

262 LESSON 21 Using Other Strategies