This is the answer key of Volume 8 of the entire set of 12 volumes of word problems solving strategies. If you want to set a solid foundation in math, grasping the techniques on solving word problems is the key to it. This set of books teaches you the techniques and strategies you need to solve word problems.
Sample question in this volume:
A lion can live up to 40 years and an elephant can live twice as long. If a sea turtle can live 20 years more than twice as long as the elephant, how many years can the sea turtle live up to?
Reasoning and solution:
Twice= 2 groups of so we can use the 3 elements formulas to solve for one of the elements:
An elephant can live twice as long "as a lion (40 years)" so the number of years that a lion can live to is the amount in 1 group; the number of groups is 2. We multiply the number of groups, 2, with the amount in each group, 40 years, to find the total amount in the groups or the number of years that the elephant can live up to:
2 x 40=80 years
A sea turtle can live up to 20 years more than twice as long as the elephant:
We need to first find the amount that is twice as much as the elephant's age. The amount in 1 group is the age of the elephant, the number of groups is 2. Twice= 2 groups of so we can use the 3 elements formulas to solve for one of the elements:
We multiply the number of groups, 2, with the amount in each group, 80, to find total amount in the groups:
2 x 80=160 years
Secondly, we need to find 20 years more than twice as long as the elephant (160 years) or 20 years more than 160 years. We add 20 to 160 to find the number of years that the sea turtle can live up to:
20 + 160=180 years
The techniques and strategies on using the addition and subtraction reasoning and the 3 elements formulas to solve decimal word problems, on using algebra to solve word problems, and on finding the measures of internal angles in triangles are also covered in this volume. There is more in the volume than what is mentioned.
Detailed explanations of the reasoning and solving strategies for each and every problem in Volume 8 are given in this book.