Top menu: NT = Number Talks PT = Pattern Talks (hover over NT to see)
25. Today is March 17. Write down as many equations as you can, each equaling to 17.
- 102 – 83 = 17
- sqrt(289) = 17
- (15 + 4) – 2 = 17
- 42 + 1 = 17
- sqrt(9) + 14 = 17
- abs(-16 – 1) = 17
- 25 – 15 = 17
- 52 – 8 = 17
26. How would you find the area of the shaded?
This 4-leaf clover was created by drawing 4 semicircles of radius equal to 1/2 of side of square.
Student 1
- Find area of square
- Find area of circle
- Subtract circle from square, this leaves area of the 2 white parts
- Subtract 2 white parts from circle gives only the shaded parts
Student 2
Student 3
I drew in the 2 segments to hint students at this strategy.
- Find area of square
- Find area of 1 semicircle
- Multiply this by 4
- Subtract area of square from area of 4 semicircles gives you the shaded part only
Student 3
I drew in the 2 segments to hint students at this strategy.
- Find area of 1/4 of circle
- Find area of right triangle within the quarter circle
- Subtract to get half the leaf part
- Multiply this by 8
27. How much bigger is california than oregon?
Answer: California’s area is 163,695 square miles, about 1.7 times larger.
Student 1
Student 2
Student 3
- Twice as big.
- I rounded up to 100000 square miles. That times 2 to get 200000. I subtracted 1400 from 200000 because I’d rounded up, so about 198600.
Student 2
- I think California is about 1.5 times bigger.
- I took half of 98380 to get 49190. Then I added this to 98380 to get 147570.
Student 3
- I think it’s 1.7 times bigger.
- I rounded up to 100000 square miles, so around 170000 is my estimate.
28. Today is March 21. Write down as many equations as you can, each equaling to 21.
- 620 ÷ 2 – 300 + 11 = 21
- 52 – 4 = 21
- 85 – 64 = 21
- sqrt(36) × 3 + 3 = 21
- sqrt(400) + 1 = 21
- 42 × 2 – 11 = 21
- 4! – 3 = 21