Page 115 - NUMINO Challenge_B2
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13 Assumptions
Basic Concepts Crane-Turtle Method
To find the number of cranes and turtles when
only the total number of heads and legs is
given is known as the Crane-Turtle Method.
This method was introduced in an ancient
Chinese math book, The Nine Chapters on the
Mathematical Art. Problems involving the
crane-turtle method can be easily solved using
diagrams.
Example There are 6 bicycles and tricycles altogether. If the total number of
wheels is 15, how many bicycles and tricycles are there?
Class Notes
If you assume that all six are bicycles, there will be wheels. Since there are 15
wheels, add 3 more wheels. Therefore, there are
bicycles and tricycles.
Use a chart to find the number of bicycles and tricycles. List all the cases where the
total number of bicycles and tricycles is six. Then, find the case with 15 wheels.
Number of 0 1 2 3 4 56
bicycles 10
Number of 6 5 4 3 2 12
tricycles
Total number 18
of wheels
Therefore, there are bicycles and tricycles.
112 NUMINO Challenge B2
Basic Concepts Crane-Turtle Method
To find the number of cranes and turtles when
only the total number of heads and legs is
given is known as the Crane-Turtle Method.
This method was introduced in an ancient
Chinese math book, The Nine Chapters on the
Mathematical Art. Problems involving the
crane-turtle method can be easily solved using
diagrams.
Example There are 6 bicycles and tricycles altogether. If the total number of
wheels is 15, how many bicycles and tricycles are there?
Class Notes
If you assume that all six are bicycles, there will be wheels. Since there are 15
wheels, add 3 more wheels. Therefore, there are
bicycles and tricycles.
Use a chart to find the number of bicycles and tricycles. List all the cases where the
total number of bicycles and tricycles is six. Then, find the case with 15 wheels.
Number of 0 1 2 3 4 56
bicycles 10
Number of 6 5 4 3 2 12
tricycles
Total number 18
of wheels
Therefore, there are bicycles and tricycles.
112 NUMINO Challenge B2
