Post on 24-May-2015
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INTEGERSMrs. Haataja
6th Grade Math
What are integers?
Photo Credit: Ciccli Pizzettaro
Integers
Are numbers Can be positive or
negative Do NOT have
decimals Do NOT have
fractions
IntegersPOSITIVE TEMPERATURE READING ALL NUMBERS IN THIS PHOTO ARE POSITIVE
AVERAGE PER GAME VALUE IS NEGATIVE (THIS IS AN OLD IPOD!)
On a number line
On a number line
Positive integers increase in increments of one as you move to the right
Negative integers mirror this moving to the left of zero, however, even though they appear to be getting bigger, they are actually getting smaller
-5 is one number smaller than -4, for example
Adding integers
You already know how to add positive integers…you just haven’t called them integers before!
Adding POSITIVE integers
5 + 3 = 8 You just added the integers positive 5 and
positive 3 and found out the answer was positive 8!
Adding NEGATIVE integers
Adding negative integers is just like adding positive integers…only difference…the answer will have a negative sign
-6 +(-5) = -11 All you do is ignore the negative signs
and add the numbers, then put the negative sign back in your answer
THIS ONLY WORKS IF BOTH NUMBERS ARE NEGATIVE!!
Adding integers with different signs
Adding integers with different signs
On the previous slide we saw a diagram of the problem 6 + (-2)
To solve this, they started at zero and moved to the right 6 places – to represent the positive 6
Next, they moved left 2 places – this represented the -2
They landed on the number 4 (positive 4) which is the answer
Adding integers with different signs
Using a number line is a great way to practice when you are first learning to add numbers with different signs – but there is another way
We can use the absolute value of a number and subtraction to solve addition problems involving integers of different signs
What is absolute value?
Absolute Value
Absolute value is the distance between a number and zero
It does not matter which direction you are moving to get back to zero – all that is important is how many steps it takes to get there
It is written as vertical lines on either side of a number
|12|, is 12 |-23|, is 23 Absolute values are ALWAYS positive
Adding integers with different signs
Here’s how with the help of absolute value…
1) find the absolute value of each number being added
2) subtract the smaller absolute value from the larger absolute value
3) the sign of the number with the larger absolute value is the sign of the answer
4 problems with two integers
21 + 29 = 50 -21 + (-29) = -50 29 + (-21) = 8
|29| = 29 |-21| = 2129 – 21 = 829 is +, so answer is + 21 + (-29) = -8
|-29| = 29 |21| = 2129 – 21 = 829 is -, so answer is -
Works cited
All photos from flickr.com, all have a creative commons license
Slide 2: Photographer: Ciccio Pizzettaro Title: Question Mark Taken: 1/23/2010 Slide 3: Photographer: Kenyee
Title: Floating Integers Taken: 8/22/2008 Slide 4 Photographer Rob Friesel found_drama
Title: Is that a…positive integer? Taken: 1/25/2013 Slide 4: Photographer: Frank Wales
Title: I should have quit while I was ahead Taken: 11/19/2007
Works cited
Slide 5: Photographer: Ethan HeinTitle: Even Integers Subgroup Taken: 4/11/2008 Slide 10: Photographer gfinder
Title: Goalfinder Math integer-numberline 1 Taken: 3/1/2012 Slide 13 Photographer: gfinder
Title: Goalfinder Math Absolute-value-of-an-integer Taken: 3/1/2012 Slide 16 Photographer danmachold
Title: clock Taken: 2/3/2011