In this video we use algebra tiles to explain how to add integers.
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In the video above, we added integers using Algebra tile, another way to thing about adding integers is by using a number line. Remember: if a number does not have a sign it is positive, so ${^-5} + 3$ is the same as saying negative 5 plus positive 3.
A negative number plus a positive number:
Ex. 1 Lets look at the problem ${^-5} + 3$.
To do this problem lets pretend that you are walking along a number line. First you would start by standing on the first number (in this case ${^-5}$.)
Because this is an addition problem you will be facing as if you were to walk toward the positive numbers.
Since the $3$ is positive, you would move forward $3$ spaces.
A positive number plus a negative number:
Ex. 2 $5 + {^-3}$
First you would start by standing on the first number
(in this case ${^+5}$) Because this is an addition problem you will be facing as if you were to walk toward the positive numbers.
Since the $3$ is negative, and a negative sign can mean “take the opposite”, you would move backwards $3$ spaces.
A negative number plus a negative number:
Ex. 3 ${^-5} + {^-3}$.
First you would start by standing on the ${^-5}$. Because this is an addition problem you will be facing as if you were to walk toward the positive numbers.
Since the $3$ is negative you would move backwards $3$ spaces.
A positive number plus a positive number:
Ex. 4 I am sure we all remember that $5 + 3 = 8$.
Try the problem $7 + {^-8}$ on your own then check your answer with the video below.
