ESTIMATION

• When you don’t need an exact answer, estimation is a good way to quickly figure out a math problem. This skill can be especially helpful in real life when you are in certain situations, such as shopping with a limited amount of money.  You can round the cost of items up to the nearest dollar and add each item in your head as you shop. This can save you the embarrassment of not having enough money when it comes time to pay at the cash register. Before you even do the shopping for a project you are planning, you can use estimation to figure out about how much the project will cost.  Businesses that provide services, such as car repair, will often give an estimate before they begin working so that the customer can decide whether or not they want to spend that amount of money on the repair.

• Estimation is also very useful when you want to check to see whether or not your exact answer is reasonable for the problem you are solving. Use rounding to get an approximate answer. Your estimate should be fairly close to your exact answer. An estimate that is off by a thousand or more could help you recognize a mistake you may have made in place value. This is especially true when you have long columns of numbers to add together, or very large numbers with carrying or regrouping. If you make it a habit to check your answers using estimation, you will avoid making silly mistakes.

 Name:__________________________________

Answer the following questions based on the reading passage. Don’t forget to go back to the passage whenever necessary to find or confirm your answers.

1)  What is one situation where you might want to use estimation?   

2)  Based on the reading passage, what do you think the word reasonable means in the second paragraph?  

3)  What should you do if your estimate is a lot different from your exact answer?

4)  Why should you always check your answers using a second method of problem solving, such as estimation?

5)   When have you used estimation? Explain.