Page 116 - NUMINO Challenge_B2
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Basic Concepts Assumptions
The Crane-Turtle problem can be solved using assumptions. Assume that all
of the heads are cranes, then use the remaining number of legs to find the
number of cranes and turtles.
Example There are 10 cranes and turtles altogether. The total number of
legs is 26. How many cranes are there?
Class Notes
If you assume that all of the animals are cranes, there are 10 legs. Since
there are 26 legs, 26 legs are left.
The 6 remaining legs are turtle legs. When one crane is replaced by a turtle, the
number of legs increases by two. Therefore, there are 2 turtles.
Therefore, there are 10 cranes.
Try It Again The total number of squids and octopuses is 8. A squid has 10
legs and an octopus has 8 legs. If the total number of legs is 68,
find the number of squids and the number of octopuses.
113Communication
The Crane-Turtle problem can be solved using assumptions. Assume that all
of the heads are cranes, then use the remaining number of legs to find the
number of cranes and turtles.
Example There are 10 cranes and turtles altogether. The total number of
legs is 26. How many cranes are there?
Class Notes
If you assume that all of the animals are cranes, there are 10 legs. Since
there are 26 legs, 26 legs are left.
The 6 remaining legs are turtle legs. When one crane is replaced by a turtle, the
number of legs increases by two. Therefore, there are 2 turtles.
Therefore, there are 10 cranes.
Try It Again The total number of squids and octopuses is 8. A squid has 10
legs and an octopus has 8 legs. If the total number of legs is 68,
find the number of squids and the number of octopuses.
113Communication
