NUMERICAL ESTIMATION STRATEGIES 10 b

ANSWER SHEET: This answer sheet gives you the answers to worksheet #2 for this concept/skill. Remember that it is important to round your numbers before performing any operations to solve the problem.

Answers to Worksheet #2:

1. The difference between the two temperatures is about 40°F. First, I rounded 65°F up to 70°F. Next, I rounded 32°F down to 30°F. Finally, I subtracted 30°F from 70°F to get the answer 40°F.

2. Frank has about 80 cookies. First, I rounded 48 up to 50. Next, I rounded 31 down to 30. Finally, I added 50 and 30 to get the answer 80.

3. There were about 400 circus tickets sold over the weekend. First, I rounded 239 down to 200. Next, I rounded 187 up to 200. Finally, I added 200 and 200 to get the answer 400.

4. The third grade sold about 100 cupcakes. First, I rounded 63 down to 60. Next, I rounded 38 up to 40. Finally, I added 60 and 40 to get the answer 100.

5. The class won about 40 prizes. First, I rounded 18 up to 20. Next, I rounded 21 down to 20. Finally, I added 20 and 20 to get the answer 40.

6. Fred needs about 80 party hats. First, I rounded 33 down to 30. Next, I rounded 47 up to 50. Finally, I added 30 and 50 to get the answer 80.

7. The ribbon is about 220 inches long. First, I rounded 83 down to 80. Next, I rounded 138 up to 140. Finally, I added 80 and 140 to get the answer 220.

8. There were about 180 flowers planted. First, I rounded 56 up to 60. Next, I rounded 117 up to 120. Finally, I added 60 and 120 to get the answer 180.

9. There were about 210 sandwiches sold. First, I rounded 148 up to 150. Next, I rounded 57 up to 60. Finally, I added 150 and 60 to get the answer 210.

10. Michael has about 80 comic books. First, I rounded 35 up to 40. Next, I rounded 42 down to 40. Finally, I added 40 and 40 to get the answer 80.