ACE 3.1 Intro to Multiplication with Integers

LARGE GROUP
The students considered the following puzzler as a warm up problem. Class 7A should consider this problem further, and both classes should share this with their families!

String Burning Puzzle

You have 2 pieces of string of different, unspecified length, and some matches. Each piece of string takes exactly an hour to burn, but the burn rate is not constant. This means that it could take 59 minutes to burn the first 1⁄4, and 1 minute for the rest. The strings have different burn rates, and of course you don't know the rates anyway. Using only the matches and the strings, measure 45 minutes.

Then we worked on Problem 3.1, Introducing Multiplication of Integers, looking at a number line model to see whether products are positive or negative when we multiply integers together. Some students also worked on Problem 3.2, Multiplication Patterns. We found that like addition, multiplication is commutative. If you switch the position of factors in an equation, the product is still the same.

Algorithms for multiplication students came up with called for multiplying the absolute values of numbers together. When multiplying two positive or two negative numbers, the product will be positive. When multiplying a positive and negative number together, the product will be negative. Class notes may be downloaded here for class 7A or class 7B.

LARGE GROUP ACE 3.1 Homework:
Please choose one of the options below to complete.

Option 1
Problems 1-4 on pages 50-51

Option 2
Problems 2-4, 24, and 30 on pages 51-56

Do not use a calculator!
Due tomorrow, Thursday, April 8.

SMALL GROUPS
Students worked with Cory today on Problem 3.1, Introducing Multiplication, parts A1-5, B1-4, and B6.

SMALL GROUP ACE 3.1 Homework:

Problems 1-4 on pages 50-51

Do not use a calculator!
Due tomorrow, Thursday, April 8.