Math Alliance June 29, 2010 Beth Schefelker, DeAnn Huinker, Melissa Hedges & Chris Guthrie

We are learning to…  Use contextual situations to explore the meaning of division You will be successful when…  Explain why the various division procedures are valid based on the meaning of division.

Four friends are going on vacation together. They decide to rent an RV. The cost for the RV is $ They agree to equally split the cost. How much will each friend pay? No U.S. standard algorithm please!

 Share your strategy with your neighbor.  What language was used to explain the strategy? Now…  Use place value models to demonstrate your strategy.  How did the place value models ◦ support your use of concept-based language? ◦ push you to visualize the situation differently?

 Turn and Talk: ◦ What is division?  Beckmann ◦ Two natural ways to interpret division and both are useful.

Context #1 Evan has 24 apples. He put them into bags containing 6 apples each. How many bags did Evan use? Context #2 Evan has 24 apples. He shares them equally among 6 friends. How many apples will each friend get? What is the answer in each context? How might a young child model each problem?

But is it?

 Context #1 – Measurement Evan has 24 apples. He put them into bags containing 6 apples each. How many bags did Evan use? ◦ Known: Size of group ◦ Unknown: Number of groups  Context #2 – Partitive Evan has 24 apples. He shares them equally among 6 friends. How many apples with each friend get? ◦ Known: Number of groups ◦ Unknown: Size of groups

Javier has 8 marbles. If he puts 2 marbles in each bag, how many bags will he need? Measurement asks “how many groups?” Javier has 8 marbles. He equally shares them with his friend Jesús. How many marbles will each boy get? Partitive asks “how many are in each group?”

 Read each problem.  Act out each problem with the counters using the “Division Work Mat.”  Identify if the problem is a measurement or partitive situation.  Draw a sketch. Write an equation. Label each accordingly

 Homework ◦ Read pp from Beckmann ◦ Complete these problems following the instructions in the book:  p. 187 #1  p. 191 #1a, #1b, #1e  Due July 6, 2010