NUMERICAL ESTIMATION STRATEGIES 10 b

ANSWER SHEET: This sheet gives you the answers to worksheet #3 for this concept/skill.

Remember that it is important to round your numbers before performing any operations to solve the problem.

Answers to Worksheet #3:

1. The difference between the two temperatures is about 60°F. First, I rounded 93°F down to 90°F. Next, I rounded 28°F up to 30°F. Finally, I subtracted 30°F from 90°F to get the answer 60°F.

2. Fidel has about 300 stamps. First, I rounded 137 down to 100. Next, I rounded 213 down to 200. Finally, I added 100 and 200 to get the answer 300.

3. There are about 220 animals at the zoo. First, I rounded 164 down to 160. Next, I rounded 58 up to 60. Finally, I added 160 and 60 to get the answer 220.

4. The third grade sold about 400 candy bars. First, I rounded 256 up to 300. Next, I rounded 112 down to 100. Finally, I added 300 and 100 to get the answer 400.

5. There were about 130 points scored during the basketball game. First, I rounded 58 up to 60. Next, I rounded 72 down to 70. Finally, I added 60 and 70 to get the answer 130.

6. Felipe needs 50 invitations. First, I rounded 16 up to 20. Next, I rounded 33 down to 30. Finally, I added 20 and 30 to get the answer 50.

7. The rope is about 100 inches long. First, I rounded 43 down to 40. Next, I rounded 57 up to 60. Finally, I added 40 and 60 to get the answer 100.

8. There are about 120 trees in the park. First, I rounded 47 up to 50. Next, I rounded 68 up to 70. Finally, I added 50 and 70 to get the answer 120.

9. There were about 200 pizzas sold. First, I rounded 129 up to 130. Next, I rounded 73 down to 70. Finally, I added 130 and 70 to get the answer 200.

10. Melissa has about 30 rings. First, I rounded 19 up to 20. Next, I rounded 6 up to 10. Finally, I added 20 and 10 to get the answer 30.