Math 156 Questions

# 28 Sections 3.1

Find the exact value of each expression in Exercise 28, 30, and 32. Use any mental calculation technique you choose. Name the technique you use in each case.

9 x 17

30 + 488

6 x 22 x 5

# 40
Give an example of a multiplication calculation that might be easy to do mentally. Then give an example. Then give an example of a multiplication calculation that is not easy to do mentally. Explain your choices.

Section 3.2

Question #42 – # 46

Give an estimate for each expression. Then state whether you believe that the exact answer is greater than or less than the estimate. Explain how you decided. Use a calculator to check the accuracy of your estimate.

978 x 66

54 x 23

12 x 26

Question #50

Name the estimation technique or techniques used in Exercise 50

146 68: I thought that 14 and 7 are easy to divide, so I used 140 70, which is 2. The quotient is about 2.

Math 156 Questions

# 28 Sections 3.1

Find the exact value of each expression in Exercise 28, 30, and 32. Use any mental calculation technique you choose. Name the technique you use in each case.

9 x 17

30 + 488

6 x 22 x 5

# 40
Give an example of a multiplication calculation that might be easy to do mentally. Then give an example. Then give an example of a multiplication calculation that is not easy to do mentally. Explain your choices.

Section 3.2

Question #42 – # 46

Give an estimate for each expression. Then state whether you believe that the exact answer is greater than or less than the estimate. Explain how you decided. Use a calculator to check the accuracy of your estimate.

978 x 66

54 x 23

12 x 26

Question #50

Name the estimation technique or techniques used in Exercise 50

146 68: I thought that 14 and 7 are easy to divide, so I used 140 70, which is 2. The quotient is about 2.