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Week 6. *sign in! (are you here?). Warm Up (wait on handing in class notes). Can you explain what is going on here? 15 • 24 =. Agenda. A note on class notes Homework for Exploration 3.13 Complete Exploration 3.13 Properties of Multiplication More Exploration 3.13 Assign Homework.
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*sign in! (are you here?) Warm Up(wait on handing in class notes) • Can you explain what is going on here? 15 • 24 =
Agenda • A note on class notes • Homework for Exploration 3.13 • Complete Exploration 3.13 • Properties of Multiplication • More Exploration 3.13 • Assign Homework
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.
Exploration 3.13 • Use Egyptian Duplation for 14 • 41.
Exploration 3.13 • 14 • 41: • 41 • 82 • 164 • 328 • 656 • Now: 14 • 41 = (2 + 4 + 8) • 41 = 82 + 164 + 328 = 574
Exploration 3.13 • Use Egyptian Duplation for 65 • 17.
Exploration 3.13 • Do this one with your partner: 65 • 17 • 65 • 130 • 260 • 520 • 1040 • 65 • 17 = 65 • (1 + 16) = 65 + 1040 = 1105
Multiplication • Vocabulary: • A•B = 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
Properties of Multiplication • zero property • identity property • commutative • associative • distributive (links multiplication and addition together!)
4 5 2 8 0 8 1 0 3 2 4 0 1 2 6 0 Exploration 3.13 • Lattice Multiplication--this is used today in certain schools. Kids love this! • 45 • 28
4 5 2 8 0 8 1 0 3 2 4 0 1 2 6 0 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
1 3 1 3 2 7 2 7 2 1 Exploration 3.13 • You try Lattice Multiplication for 27 • 13 thousands hundreds tens 2 7 ones 6 3 5 1
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.
Homework--Due Wednesday • Section 3.3 pp. 186 - 189 1, 9, 12, 14b, 18, 19bd; 21, 42, 50, 53