Black and red chips

Observations: 

-black and red equal or more black than red 

-net value is the sum (reds+black=net value) 

-net value=blacks-reds 

-blacks =red ---net value =0

-odd total #of tiles net value not equal to 0. 

-if one or more red than black NV is -1 

-if one more black than Ed is 1

What is addition and what is subtraction? 

Class definitions 

Addition: putting stuff together

Subtraction: difference between 2 things-- take away 

put in other picture

We had a confusion: we had a total number of 7 tiles. 2 red tiles. 5 black tiles. a net value of +3. 

The class had 2 different equations:

Advik: 5-2=3 Took away (Subtraction)

Corinna: -2+5=3 Added Negatives (addition) 

What is the same? The answer. 

Does it matter which math sentence? 

yes. Why? 

Two different things are happening. In one place you are gathering something and in the other you are taking them away. 

L63 Homework: 

Write a good word problem to go with each of those equations.

5+-2=3

5-2=3

Make a prediction: 

what happens if I add 2 positive numbers? 

what happens if I add 2 negative numbers? 

what happens if I add 1 positive and 1 negative number?

Homework: 

L62 pg. 22 #23-35