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*sign in! (are you here?). Week 6. Warm up Problem: Without doing any calculation, explain why 35 base 7 > 35 base 6. Agenda. Discuss Exams Multiplication Models Begin Exploration 3.13 Assign Homework. 4 feet. 2 feet. Meanings for Multiplication. Repeated addition:
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*sign in! (are you here?) Week 6 Warm up Problem: Without doing any calculation, explain why 35 base 7 > 35 base 6.
Agenda • Discuss Exams • Multiplication Models • Begin Exploration 3.13 • Assign Homework
4 feet 2 feet Meanings for Multiplication • Repeated addition: • 3 • 4 = 4 + 4 + 4 = 12 • 4 • 3 = 3 + 3 + 3 + 3 = 12 • Area: 4 • 2 =
Shirt 1 Shirt 2 Shirt 3 J B R K C J B R K C J B R K C Meanings for Multiplication • Measured Units: 5 times x units long • Cartesian Product: combinations e.g., 3 shirts, 5 pair pants
Meanings for Multiplication • Arrays: 3 • 5
Meanings for Multiplication • Rate: 8 miles per hour for 5 hours: • 8 • 5 = 40 miles
Exploration 3.13 • First, read through the Egyptian Duplation example. Focus on the Hindu-Arabic numerals. (You can ignore the Egyptian Numerals.) • With a partner, can you explain what is going on here?If so, can you explain why it works? • With your partner, see if you can do 14 • 41; 65 • 17; 18 • 37. Do not use a calculator!!
Homework • Due Wednesday • Read Section 3.3 (up to page 178 – the multiplication algorithm) • Class Notes Packet 1. Do Children’s Thinking Activity 1 (pp. 1-3). Write your answers directly in the packet. • Due Friday • Exploration 3.13 1. Do Egyptian Duplation and Lattice Multiplication for the following problems:(a) 19 • 73 (b) 26 • 50 (c) 7 • 94 2. Try to write in words why mathematically each algorithm works.