Content Area: Math

 

Index: 4.1B Grade 8 CPI 5

 

Standard: 4.1 - Number and Numerical Operations

 

Strand: B - Numerical Operations

 

Cumulative Progress Indicator: 5 -  The student will understand and apply the standard algebraic order of operations, including appropriate use of parentheses.

 

Grade: 8

 

Sample  Activities:

 

·        Students bring in calculators from home to examine their differences. Among other activities, they each key in " 6 + 2 x 4 = " and then compare their calculator displays. Some of the displays show 32 and others show 14. Why? Which is right? Are the other calculators broken?

 

·        Students play rolling numbers. They use four white dice and one red one to generate four working numbers and one target number. They must combine all of the working numbers using any operations they know to formulate an expression that equals the target number. For example, for 2, 3, 4, 5 with target number 1, the following expression works: (2+5)/(3+4)=1. Questions about order of operations and about appropriate use of parentheses frequently arise.

 

·        Students bring in calculators from home to examine their differences. Among other activities, they each key in "3 + 15 ÷ 3" and then compare their calculator displays. Some of the displays show 6 and others show 8. Why? Which is right? Are the other calculators broken? Students decide what key sequence would work for the calculators that do not use order of operations.

 

·        Students play with the software How the West was One + Three x Four, which requires them to construct numerical expressions that use the standard order of operations.

 

·        Students use the digits 1, 2, 3, and 4 to find expressions for each of the numbers between 0 and 50. For example, 7 = (3x4)/2 + 1.