Problem Description:
The task involves rounding numbers to the nearest 10 and the nearest 100. Here's a breakdown of the problem:
1.
Rounding to the Nearest 10:
- If the digit in the ones place is 5 or greater, round up.
- If the digit in the ones place is less than 5, round down.
2.
Rounding to the Nearest 100:
- If the digit in the tens place is 5 or greater, round up.
- If the digit in the tens place is less than 5, round down.
Solution:
#### Part 1: Rounding to the Nearest 10
1.
35: The ones digit is 5, so round up.
Answer: 40
2.
78: The ones digit is 8, so round up.
Answer: 80
3.
13: The ones digit is 3, so round down.
Answer: 10
4.
65: The ones digit is 5, so round up.
Answer: 70
5.
58: The ones digit is 8, so round up.
Answer: 60
6.
42: The ones digit is 2, so round down.
Answer: 40
7.
49: The ones digit is 9, so round up.
Answer: 50
8.
31: The ones digit is 1, so round down.
Answer: 30
9.
55: The ones digit is 5, so round up.
Answer: 60
10.
18: The ones digit is 8, so round up.
Answer: 20
#### Part 2: Rounding to the Nearest 100
11.
870: The tens digit is 7, so round up.
Answer: 900
12.
362: The tens digit is 6, so round up.
Answer: 400
13.
419: The tens digit is 1, so round down.
Answer: 400
14.
162: The tens digit is 6, so round up.
Answer: 200
15.
812: The tens digit is 1, so round down.
Answer: 800
16.
450: The tens digit is 5, so round up.
Answer: 500
17.
525: The tens digit is 2, so round down.
Answer: 500
18.
699: The tens digit is 9, so round up.
Answer: 700
19.
360: The tens digit is 6, so round up.
Answer: 400
20.
250: The tens digit is 5, so round up.
Answer: 300
Final Answer:
\[
\boxed{
\begin{array}{ll}
1. 35 \to 40 & 11. 870 \to 900 \\
2. 78 \to 80 & 12. 362 \to 400 \\
3. 13 \to 10 & 13. 419 \to 400 \\
4. 65 \to 70 & 14. 162 \to 200 \\
5. 58 \to 60 & 15. 812 \to 800 \\
6. 42 \to 40 & 16. 450 \to 500 \\
7. 49 \to 50 & 17. 525 \to 500 \\
8. 31 \to 30 & 18. 699 \to 700 \\
9. 55 \to 60 & 19. 360 \to 400 \\
10. 18 \to 20 & 20. 250 \to 300 \\
\end{array}
}
\]
Parent Tip: Review the logic above to help your child master the concept of rounding worksheet third grade.
