Question

Suppose you want to buy software for your computer. One piece of software costs $20.75. Another costs $10.59 and a third costs $18.25.

Use mental math to find the total cost. Explain.
How much more is the first piece of software than the second? Use mental math to decide.

Answer 1

The total cost is 49.59 the answer for the second question is 10.16

Explanation:

Part A. self explanatory, i just added all of the pieces together and got 49.59.

Part B. I just solved the expression 20.75 - 10.59 and got 10.16.