4 6 $1.60
5 5 $1.75
6 4 $1.90
Hence, 6 quarters and 4 dimes are needed to get $1.90.
EVALUATION: Six quarters plus 4 dimes makes 10 coins whose value is
$1.90. The answer is correct.
EXAMPLE:In a children’s parade there are 12 children, some riding bicycles
and some riding tricycles. If there is a total of 32 wheels, how many children
are riding a bicycle and how many are riding a tricycle?
SOLUTION:
GOAL: You are being asked to find how many children are riding a bicycle
and how many are riding a tricycle.
STRATEGY: You can make an organized list as shown:
Bicycles (2 wheels) Tricycles (3 wheels) Total wheels
11135The number of bicycles and tricycles must sum to 12 since there are 12
children.
IMPLEMENTATION: Continue the table until the correct answer (32
wheels) is found.
Bicycles (2 wheels) Tricycles (3 wheels) Total wheels
11135
21034
3933
4832Hence there are 4 children riding bicycles and 8 children riding tricycles.
EVALUATION: Since 8þ 4 ¼12 and 4 bicycles have a total of 8 wheels and
8 tricycles have a total of 24 wheels, 8þ 24 ¼32.
LESSON 21 Using Other Strategies 257