Operations with Integers Jenny Ray Kentucky Department of Education March 2013

Build on what students know… Temperature If the temperature at 8:00AM is 43 degrees, Fahrenheit, and the temperature at 5:00PM is 62 degrees Fahrenheit, what is the change in temperature, in degrees Fahrenheit? Show your thinking on the thermometer.

Build on what students know… Temperature When a traveler leaves Paris, the temperature is 72*F; when the traveler arrives in Beijing, the temperature is -12*F. What is the change in temperature from Paris to Beijing? Show your thinking on the thermometer.

Transfer to a number line…

4 – 6 = ____

What about -7 – (-2) ? This becomes more difficult to model on a number line, unless you think of it as -7 then the opposite of (-2), which is positive 2. Let’s try another model, also…

2-Sided Counters RED is Positive; Yellow is Negative

Use Counters to Model… 6 + (-2) = -7 + 4 = -5 + (-3) = NOW TRY: 6 – 3 = -4 – 5 = 3 – (-2) =

Multiplication of Integers 2 x 4 2 x -4 -2 x -4

Solving One-Variable Equations Use the counters and cups to solve for the variable: 2x + 3 = -7 ½ x + 3 = -7 3/2 x + 3 = -7

To download the PPT… www.JennyRay.net Resources 6-12 Resources