Aim: How can a chip model or number line be useful in determining an algorithm for subtraction?
Homework: Txtbk p.45 #18-29
1. What is the algorithm we determined last class for the addition of integers?
2. Without finding the sum determine whether the following will be positive, negative, or zero.
12 + (-16) + 20 + (-17)
Classwork: We explored subtraction problems with integers and understood this central point: subtracting a negative is the same as adding a positive AND subtracting a positive is the same thing as adding a negative.
Announcements: I will be offering extra help on Tuesdays after school in room 228. The first session meets tomorrow.