1.2, Estimation

Rounding
- Select the digit you wish to round to. Call this d
- Look at the digit to the immediate right. Call this r
  - if it is <5, do nothing
  - If it is ≥5, add 1 to d and carry if necessary.
- 2.3 rounds to 2
- 2.5 rounds to 3
- 2.7 rounds to 3
Estimation - the process of arriving an an approximate answer to a question.
Why do we estimate?
- To get a general idea about an answer to a question
- To check a more complex computation.
How do we estimate?
- Round the numbers to reasonable values.
- Perform the computation.
What do we round to?
- This depends on the computation.
- Addition/subtraction, round to the same place.
- Multiplication/division whatever is reasonable.
- It also depends on What type of answer we want.
- Sometimes, like with money, we want to round everything up.
Problem 2, Page 14
Problem 4, 8
Problem 14, 16, 18

1.3, Problem Solving