Lessons for 9/18

Course 2: Adding Integers

Remember our song/poem for adding integers:
"Same signs add and keep,
Different signs subtract,
Keep the sign of the higher number,
Then it will be exact."

Here's another way of writing the Rules:
When the integers have the SAME signs:
1. Add the numbers together.
2. Keep the same sign.

When the integers have DIFFERENT signs.
1. Ignore the signs.
2. Subtract the 2 numbers.
3. Give the answer the sign of the larger number (number with greater absolute value).

Here's are a couple Khan Academy videos explaining this concept:

 

 

 

 

Pre-Algebra: Subtracting Integers

Remember, to subtract simply "add the opposite."

 

Think LCO:

1. Leave the first number.

2. Change subtraction sign to addition sign.

3. Change the second number to it's opposite.

 

After you've changed your problem to adding, follow our addition rules (listed above...think about singing!).

 

 

Here's a Khan Academy video to guide you: