For each subtraction problem, circle the correct calculation.

1. \(7.2 - 3.67\)

   

   on left, 7 and 2 tenths - 3 and 67 hundredths = 3 and 5 hundredths.

   

   0, 7 and 2 tenths - 3 and 67 hundredths = 3 and 5 hundredths.

   

   on right, 7 and 20 hundredths - 3 and 67 hundredths = 3 and 53 hundredths.

2. \(16 - 1.4\)

   

   on left, 16 - 1 and 4 tenths = 2 tenths.

   

   middle, 16 and 0 tenths - 1 and 40 hundredths = 20 hundredths.

   

   on right, 16 and 0 tenths - 1 and 4 tenths = 14 and 6 tenths.

Explain or show how you could find the difference of 1 and 0.1978.

A chemist orders a jar labeled to contain 0.384 kilogram of a chemical she needs for an experiment. The actual weight of the chemical sample she receives is 0.3798 kilogram.

1. Is the chemical sample heavier or lighter than the weight stated on the label? Explain how you know.

2. How much heavier or lighter is the sample than stated on the label? Show your reasoning.

Complete the calculations so that each shows the correct sum.

a, 1 point 0 3 6 plus an unknown quantity with four digits is equal to 4.

b, 0 point 7 3 8 plus an unknown quantity with four digits is equal to 1.

c, 0 point 5 1 3 7 plus an unknown quantity with five digits is equal to 1.

A shipping company is loading cube-shaped crates into a larger cube-shaped container. The smaller cubes have side lengths of \(2\frac12\) feet, and the larger shipping container has side lengths of 10 feet. How many crates will fit in the large shipping container? Explain your reasoning.

For every 2 students, the art teacher prepares 9 cups of clay.

1. Here is a double number line diagram showing varying numbers of students and the cups of clay prepared. Complete the missing information.

   

2. The same information is shown on a table. Complete the missing information.

   cups of clay	number of students
   9	2
   	4
   27
   	14
   	1

   Then, answer these questions:

   • How many students are there if the teacher prepares 63 cups of clay?
   • How many cups of clay are needed for 20 students?
   • How many cups of clay are prepared for each student?