Integer2

Adding integers is one of the MOST important concepts that you learn in Pre-Algebra. From here, you're able to work with rational numbers, polynomials, and much much more. But if we have troubles with integers, those other concepts later on will be even harder. So, let's make sure that you understand it.

One way to think about adding integers is to model each integer on a number line. Start the second integer where the first one ends. The solution is where the second integer ends.

Another way is to use Algebra tiles. Model the first integer, then model the second. You can find the solution by counting how many tiles are there "in all". (Remember that phrase from 1st grade?)

Pull out your Algebra tiles. Model the following expression with your algebra tiles: 4 + 6 Answer

Easy? Yes, you've been doing this since 1st grade. But we have to start somewhere we know before adding anything new.

Try another one. 7 + 5 Answer


 * Write a rule for adding positive integers together in the [|discussion board].**

What about negatives? On a number line, make sure that your arrows are pointed to the LEFT. (That's the negative direction.)

Now, try modeling this situation with your algebra tiles: (-3) + (-8) Answer

The parenthesis are there just to make sure that YOU know that these are negative numbers. You could write it like -3 + -8 and still get the same answer. Remember, you only have negative integer tiles, so your answer MUST be negative.

Try another one (-10) + (-2) Answer


 * Write a rule for adding negative integers together in the [|discussion board].**

Time for a break. No...not that kind of break. (And if you don't get the reference...ask Mom.)

This fun video shows what happens when you add integers of opposite signs.
 * media type="youtube" key="53dSP5IM5CY&hl=en" height="355" width="425" ||
 * Video by [|AndrewT3660] ||

Wow! Someone had WAY too much time on their hands!

Think about the last example that the video showed: -3 + 3 = 0 Negative three and positive three are opposites. I call these __**zero pairs**__. Whenever you add opposites or zero pairs, you end up with zero.
 * 4 + -4 = 0
 * -250 + 250 = 0
 * 156872354awejrk + -156872354awejrk = 0

So, how does this work with Algebra tiles?

media type="custom" key="847963"


 * Write a rule that you can remember that describes how to add to opposite integers together in the [|discussion board].**

Adding integers of opposite signs is a lot like a war. (Remember the video?) Who will survive? Whoever has more to start off with.

media type="custom" key="848079"

Don't forget that we can do it with a numberline.

Do you see the shortcut? (think subtraction)


 * Write a rule for adding integers of opposite signs together in the [|discussion board].**

Before you start the homework, go to the [|cool interactive example]. Try at least 5 of them. (The colors are different, but it's still similar to your algebra tiles.) The application takes some time to load.

HOMEWORK TIME: (you'll need to use the printer.)

Day 1: What are Integers? Day 2: Adding Integers Day 3: Subtracting Integers Day 4: Multiplying Integers Day 5: Dividing Integers Day 6: Test