“The Money Vault”
Summative Assessment Key
An Algebra 1 book is 12.5 in long, 10.5 in wide, and 2 in thick. Ms. River’s classroom measures 20 ft
long, 19.4 ft wide, and 12.9 ft tall.
1. What is the area of the cover of the textbook? Use words, math operations, or pictures to show your
answer. Write your answer in square units.
The area of the book’s cover is 131.25 square inches. Students should explain that they
multiplied the length times the width.
2. What is the volume of the classroom? Use words, math operations, or pictures to show your answer.
Write your answer in cubic units.
The volume of the classroom is 5,005.2 cubic feet. Students should indicate that they found this
volume by multiplying the length, width, and height measurements.
3. What is the volume of the textbook? Use words, math operations, or pictures to show your answer.
Write your answer in cubic units.
The volume of the textbook is 262.5 cubic inches. Students will likely show how they found their
answers in one of two ways: (1) multiply the length, width, and height measurements, or (2)
multiply the area measurement from the first problem (131.25 square inches), and then
multiplying that by the height of 2 inches.
4. About how many textbooks can fit in the classroom? Explain your answer and be sure that your units of
measurement are the same.
Before finding their estimation, students must convert the volumes of the textbook and
classroom to the same units of measurement. Converting the classroom’s volume to cubic
requires multiplying the volume of the classroom by 1,728 (12 x 12 x 12 for the three
dimensions of a cubic foot in inches). The volume in cubic inches is 8,648,985.6.
By dividing the volume of the classroom by the volume of the textbook, we see a good
estimation is between 32,948 and 32,949 textbooks total.
Volume of the classroom
Volume of the textbook
=
8,468,985.6
262.5
≈ 32,948.5