Junior Cert Complete 3 Year Spiral Course

Video Tutorials and Exercises for the Junior Cert Complete 3 Year Spiral Course

Course Content

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Integer SubtractionDescription: To subtract an integer you change the sign of the integer and ADD it.

Objective:

The purpose of this module is to note that subtracting can be thought of as the opposite of adding and this idea can be applied to numbers that we are not familiar with such as the Integers. Subtracting can be used in other situations as well, but the method of subtracting an Integer remains the same. Additional questions can be found here

Help on this Topic:

In this question we create a formula as before, and think of people getting off a bus for negative values, or getting on the bus for positive values.

The only difference is that if we subtract a negative number, we replace that with adding a postivie number.

Example question

If Moscow is 11 degrees, and Leningrad is 4 degrees, how much hotter is it in Moscow

(#Temp in Moscow) - (#Temp in Leningrad)

->  This part at the bottom of the question is the formula, it means 

(The temperature in Moscow) subtract (the temperature in Leningrad)

So our answer is 

(11) - (4)

=7

Example question 2

If Moscow is -6 degrees, and Leningrad is -11 degrees, how much hotter is it in Moscow

(#Temp in Moscow) - (#Temp in Leningrad)

->  This part at the bottom of the question is the formula, it means 

(The temperature in Moscow) subtract (the temperature in Leningrad)

So our answer is 

(-6) - (-11)  

Whenever we try to subtract a negative number it is the same as adding a positive number so our formula is now

(-6)  + (11)

=5