Unit 3 Contents

Choosing Efficient Estimation Strategies

Mr. Moreno's students are doing science projects on gross things. Tanya and Nick went to the school store to buy posters and had $40 to spend. Tanya chose a poster of stinky, smelly stuff and Nick chose a poster of slimy, gooey stuff. The posters were $17.65 each.

They decided to estimate to see if they had enough money to buy two posters.

Nick chose $18.00 as a convenient number. He thought, “$18.00 is close to $17.65 but is easier to use because I know if I double $18.00 it is $36. Since $36.00 is less than $40.00, we have enough.”

Since Tanya and Nick had $40 to spend, both estimates worked to predict that they had enough money to buy the posters.

11. Nick's poster of slimy, gooey things shows that everyone makes 7 liters of spit per week. There are 26 students in Mr. Moreno's class. What convenient numbers can Nick use to make a reasonable estimate of how much spit the class makes in a week?
12. Tanya's poster of stinky, smelly stuff shows that each person burps about 105 times a week. There are 23 students in the library. Tanya estimated that these 23 students will burp about 2000 times this week. Is her estimate reasonable? Explain your thinking.