2. Homework Comments

4. Can you… Show why x 0=k is not true for nonzero x?

8. Explain what is wrong: “50 ÷ 7 is the same as 50 ÷ 10, (which is 5) then because I adding 3 to the divisor I now need to subtract 3: 5 - 3 = 2.”

9. Estimate 35 49. Show 3 different ways to find: 35 49. Estimate 27984 ÷ 82. Show 27984 ÷ 82 using the scaffolding method.

10. 35 49 is about 35 50. Think: 30 50 = 1500, and 5 50 = 250, so 1750. Methods: rectangular area, lattice multiplication, Egyptian Duplation, any of the methods used by the kids. 27984 ÷ 82: 82 1 = 82; 82 10 = 820; 82 100 = 8,200; 82 1000 = 82,000. So, the quotient is between 100 and 1000, and is closer to 100. Now: 8 3 = 24, so guess 300.

11. 27984 ÷ 82 82 1 = 82; 82 10 = 820; 82 100 = 8,200 82 ) 27984 24600 3384 1640 1744 1640 104 82 22 1 20 20 300

12. I’m thinking of a number. It is less than 50. When I divide it by 8, I get a remainder of 5. But when I divide it by 7, I get a remainder of 2. Use the manipulatives to find my number.

13. Do I Understand??? Given:4 7 X 3 9 4 2 3 1 4 1__ 1 8 3 3 Question: Without doing any work, what is 30 47? How do you know?

14. Do I Understand? Given: 208 R 7 18 ) 3751 36 151 144 Question: Without doing any work, what is 200 18? How do you know?

15. Make this true for order of operations 12 ÷ 4 - 2 5 = 30 What other values can we get using 12 ÷ 4 - 2 5?