CPM Homework Help : CC1MN Problem 6-105

Simplify each of the following expressions without using a calculator. Then use a calculator to check your answers.

Compute without a calculator

$0.045 + 1.2 + 62.003$
Hint (a):
Make sure you add parts that are alike. You can think of 0.045 as
$\frac{4}{100}\text{ and } \frac{5}{1000}\text{ or as }\frac{45}{1000}.$
How can you combine this with the other numbers? Be sure to show your work.
$56.7 − 0.23$
Hint (b):
$\text{You can think of 56.7 as } 56\frac{7}{10}\text{ and 0.23 as } \frac{23}{100}.$
How can you subtract $23$ hundredths from $70$ hundredths?
(7.8)(0.03)
Answer (c):
$0.234$
$6.3 − 7.5$
Hint (d):
Since $7.5$ is greater than $6.3$ , your answer should be less than zero.
Answer (d):
$−1.2$