Content Area: Math

 

Index: 4.1C Grade 3 CPI 2

 

Standard: 4.1 - Number and Numerical Operations

 

Strand: C - Estimation

 

Cumulative Progress Indicator: 2 - The student will construct and use a variety of estimation strategies (e.g., rounding and mental math) for estimating both quantities and the result of computations.

 

Grade: 3

 

Sample Activities:

 

·        Students develop and use the front end estimation strategy to obtain an initial estimate of the exact answer. For example, to estimate the total mileage in a driving trip where 354 miles were driven the first day, 412 the second day, and 632 the third, simply add all digits in the hundreds' place: 3 + 4 + 6 = 13 hundred or 1300.

 

·        Students learn to adjust the front end estimation strategy to give a more accurate answer. To do so, the second number from the left (in the problem above, the tens) is examined. Here, the estimate would be adjusted up one hundred because the 5 + 1 + 3 tens are almost another hundred. This would give a better estimate of 1400.

 

Sample Assessment Question:

 

·        Estimate 423 - 174. The difference is between which numbers?      

o       A.  0 and 199

o       B. 200 and 399

o       C. 400 and 599

o       D. 600 and 799 

 

The correct answer is B.