Content Area: Math

 

Index: 4.1C Grade 4 CPI 3

 

Standard: 4.1 - Number and Numerical Operations

 

Strand: C - Estimation

 

Cumulative Progress Indicator: 3 - The student will recognize when an estimate is appropriate, and understand the usefulness of an estimate as distinct from an exact answer.

 

Grade: 4

 

Sample Activities:

 

·        Given pairs of real-life situations, students determine which situation in the pair is the one for which estimation is the best approach and which is the one for which an exact answer is probably needed. One such pair, for example, might be: deciding how much fertilizer is needed for a lawn and filling the bags marked "20 pounds" at the fertilizer company.

 

·        Given a set of cartoons with home-made mathematical captions, third graders decide which of the cartoon characters arrived at exact answers and which got estimates. One of the cartoons might show an adult standing in the checkout line at a supermarket and another might show the checkout clerk. The captions would read: Mr. Harris wondered if he had enough money to pay for the groceries he had put in the cart and Harry used the cash register to total the bill. Students make up their own similar cartoon.

 

·        Students share with each other various situations within the past week when they and their families had to do some computation and describe when an exact answer was necessary (and why) and when an estimate was sufficient (and why).