# Estimation

Estimating is designed to be an educated guess either to (a) access prior knowledge or to (b) evaluate the reasonableness of an answer . For each of the following estimation strategies:

- Research and describe the strategy.
- Create two examples when the estimation strategy is appropriate to use (one easy, one complex).
- Create one example where the strategy is not accurate, with explanation.

For two highest place values only.

Why round up on a 5, but down on a 4?

# Mental math

The techniques for mental arithmetic are related to estimation techniques, only the accuracy of the final answer is in question. For each of the following mental math strategies:

- Describe the strategy
- Explain why the strategy works. Is the strategy similar to estimation strategies or alternate algorithms?
- Create and solve two examples using whole numbers (one easy, one complex).

## 6. Balancing, aka. compensation (+, –)

Why doesn't this say "add zeros"?

All place values.