Content Area: Math

 

Index: 4.1C Grade 4 CPI 4

 

Standard: 4.1 - Number and Numerical Operations

 

Strand: C - Estimation

 

Cumulative Progress Indicator: 4 - The student will use estimation to determine whether the result of a computation (either by calculator or by hand) is reasonable.

 

Grade: 4

 

Sample Activities:

 

·        Students are regularly asked if their answer makes sense in the context of the problem they were solving. They respond with full sentences explaining what they were asked to find and why the numerical answer they found fits the context reasonably, that is, why it could be the answer.

 

·        Fourth graders might be asked to decide if their estimated answer to the following problem is reasonable. The band has 103 students in it. They line up in 9 rows. How many students are there in each row? The students' responses might indicate, for example, that there should be about 10 students in each row, since 103 is close to 100 and 9 is close to 10.

 

·        Students estimate reasonable numbers of times that particular physical feats can be performed in one minute. For example: How many times can you skip rope in a minute? How many times can you hit the = button on the calculator in a minute? How many times can you blink in a minute? How many times can you write your full name in a minute? and so on. Other students judge whether the estimates are reasonable or unreasonable and then the tasks are performed and actual counts made. (To determine the number of times the = button is hit in a minute, press +1= so that each time the = button is pressed, the display increases by 1.)

 

·        Third-grade students are given a set of thirty cards with three-digit subtraction problems on them. In one minute, they must sort the cards into two piles: those problems whose answers are greater than 300 and those whose answers are less than 300. The correct answers can be on the backs of the cards to allow self-checking after the task is completed.

 

·        For assessment, fourth-grade students might be given a page of one-digit by multi-digit multiplication problems in a multiple choice format with four possible answers for each problem. Within some time period which is much too short for them to perform the actual computations, students are asked to choose the most reasonable estimate from each set of four answers.