Exploratory Math English LUNCH Science locker Social Studies December 18, 2014 Day B Exploratory Math English LUNCH Science locker Social Studies Day B

Opening exercise pg. 82 ACTIVATOR (December 18, 2014) : Take out your H.W & notebook. In packet, answer this: Opening exercise pg. 82

December 18, 2014 Day B SWBAT explore and discover that Euclid’s Algorithm is a more efficient means to finding the greatest common factor of larger numbers and determine that Euclid’s Algorithm is based on long division. We will show what we know when we successfully complete our ticket to go. 6.NS.B.4

Example 1 (pg. 82) What is the GCF of 60 and 100? 20

Notice that we can use the GCF of 20 to create the largest square tile that will cover the rectangle without any overlap of gaps. We used a 20x20 tile. But, what if we didn’t know this? We could start by guessing. What is the biggest square tile that we can guess? 60x60

It fits, but there are 40 units left over It fits, but there are 40 units left over. Do the division problem to prove this. What is the leftover area? 60 x 40 What is the largest square tile that we can fit in the leftover area? 40 x 40

What is the leftover area? 20 x 40 What is the largest square tile what we can fit in the leftover area? 20 x 20 When we divide 40 by 20 there is no remainder. So we have tiled the entire rectangle. If we had started tiling the whole rectangle with squares, the largest square we could have used would have been 20 by 20.

Example 2 (pg. 83)

How Do You Feel? December 18, 2014 Day B topic.

Example 3 pg. 83

Example 4 pg. 84 If we use squares that are 10 by 10, how many will we need? 3x5 or 15 squares If this were a giant chunk of cheese in a factory, would it change the thinking or the calculations we just did? no How many 10 inch by 10 inch squares of cheese could be cut from the giant 30 inch by 50 inch slab? 15

Closing Euclid’s Algorithm is used to find the greatest Common Factor (GCF) of two whole numbers. The steps are listed in your student page and need to be followed enough times to get a zero remainder. With practice, this can be a quick method for finding the GCF

December 18, 2014 Day B Ticket-to-Go Use Euclid’s Algorithm to find the greatest common factor of 45 and 75.

December 18, 2014 Day B Problem Set: Page 85

December 18, 2014 Day B Accommodations Read or reread presentation or activity directions, as needed or after prompting Use examples to model and act as a guide for emerging learners