1. Week 6

2. Warm Up (wait on handing in class notes) Can you explain what is going on here? 15 24 = *sign in! (are you here?)

3. Agenda A note on class notes Homework for Exploration 3.13 Complete Exploration 3.13 Properties of Multiplication More Exploration 3.13 Assign Homework

4. Homework Due Friday and Monday Exploration 3.13. 1. Do Egyptian Duplation (F), Lattice and Lightning Cross Multiplication (M) for the following problems: (a) 19 73 (b) 26 50 (c) 7 94 2. Try to write in words why mathematically each algorithm works.

5. Exploration 3.13 Use Egyptian Duplation for 14 41.

6. Exploration 3.13 14 41: 41 82 164 328 656 Now: 14 41 = (2 + 4 + 8) 41 = 82 + 164 + 328 = 574

7. Exploration 3.13 Use Egyptian Duplation for 65 17.

8. Exploration 3.13 Do this one with your partner: 65 17 65 130 260 520 1040 65 17 = 65 (1 + 16) = 65 + 1040 = 1105

9. Multiplication Vocabulary: AB = C A is the multiplier B is the multiplicand C is the product A and B are factors C is a multiple of A and B

10. Properties of Multiplication zero property identity property commutative associative distributive (links multiplication and addition together!)

11. Exploration 3.13 Lattice Multiplication--this is used today in certain schools. Kids love this! 45 28 2828 4 5 0 8 1 0 3 2 4 0 1 2 6 0

12. Exploration 3.13 With a partner, can you explain what is going on in Lattice Multiplication? If so, can you explain why it works? 45 28 2828 4 5 0 8 1 0 3 2 4 0 1 2 6 0

13. Exploration 3.13 You try Lattice Multiplication for 27 13 1313 2 7 1313 2 1 6 72 3 5 1

14. Homework Due Friday and Monday Exploration 3.13. 1. Do Egyptian Duplation (F), Lattice and Lightning Cross Multiplication (M) for the following problems: (a) 19 73 (b) 26 50 (c) 7 94 2. Try to write in words why mathematically each algorithm works. Write it up clearly, and be sure to explain the mathematics: For Egyptian Duplation, how the distributive property is involved. For Lattice Multiplication and Lightning Cross Multiplication be sure to explain how the place values are maintained.

15. Homework--Due Wednesday Section 3.3 pp. 186 - 189 1, 9, 12, 14b, 18, 19bd; 21, 42, 50, 53