Transcript Adding Integers
Meet Elena and Noah. Given a choice, they would rather play video games after school than do homework! Can you believe that?
They're playing a fighting game called Adding Integers. Elena is Negatron, who attacks with negative numbers and Noah is Positron, who attacks with positive numbers. Let's take a look!
Adding Opposite Numbers with the same Absolute Value
You already know integers. These are the whole numbers on the positive and negative side of the number line. They are separated by zero, just like the opponents in the game.
OK let's look at the number line to see what happens when we have to add opposite numbers with the same absolute value. Noah attacks first with a positive 3 and Elena counters with a negative 3.
You go 3 steps left for negative 3 and then 3 steps right from that point for positive 3. Adding equal and opposite numbers always equals zero. Or, if we write this as an equation: −3 + (+3) = 0.
So remember: Adding numbers with opposite signs equals zero.
Adding two Negative Numbers
Let's watch Elena and Noah play another round. This time, Elena uses Negatron's power up of negative 2. Now we have to add two negative numbers.
Negative 3 plus negative 2 means you go 3 steps left for negative 3 and then 2 more steps left for negative 2, ending up with negative 5.
Adding two negative numbers equals a negative sum.
Adding a Negative and a Positive Number
Oh no! Noah forgot to use Positron's power up! He uses the regular attack of positive 3. So now we have negative 5 and positive 3.
Again, you go 5 steps left for negative 5 and from that point 3 steps right for positive 3. Adding both arrows gives you negative 2.
We can write the equation as: −5 + (+3) = −2.
When adding a positive and a negative number, the sign of the number which has the greater absolute value "wins."

Variables

Simplifying Variable Expressions

Evaluating Expressions

Order of Operations

Distributive Property

Adding Integers

Subtracting Integers

Multiplying and Dividing Integers

Types of Numbers

Transforming Terminating Decimals to Fractions and Vice Versa

Transforming Simple Repeating Decimals to Fractions and Vice Versa

Rational Numbers on the Number Line
wow!
Great video!