1. No category

CCSS
place value
understanding
to round whole
numbers toand
the
NS 1.4G3.NBT.1
Round offUse
numbers
to 10,000
to the nearest
ten, hundred,
nearest 10 or 100.
UNDERLYING SKILLS AND CONCEPTS:
compare numbers;
order numbers;
counting
thousand.
Round to the Nearest Ten
a
K
ey Ide
When you round a number to the nearer ten, you decide
whether it is closer to the ten before or the ten after.
Numbers with 5 in the ones place are halfway between two
tens.
When a number is halfway between, you round up.
1
1
2
3
4
5
6
7
8
9 10
Use the hundred chart.
Is 47 closer to 40 or 50?
11 12 13 14 15 16 17 18 19 20
Find 47.
It is 7 squares away from 40.
It is 3 squares away from 50.
47 is closer to 50.
So, 47 rounds up to 50.
31 32 33 34 35 36 37 38 39 40
E x am p l E
21 22 23 24 25 26 27 28 29 30
2
Is 63 closer to 60 or 70?
Find 63.
It is 3 squares away from 60.
It is 7 squares away from 70.
63 is closer to 60.
So, 63 rounds down to 60.
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100
E x am p l E
3
Is 75 closer to 70 or 80?
Find 75.
It is halfway between 70 and 80.
So, 75 rounds up to 80.
page 38
Chapter 4 – Lesson 1
C – © CSL Associates, Inc. All rights reserved.
E x am p l E
Name
P RAC T I C E
Round each number to the nearest ten. You may use the chart.
1. 21
20
2. 91
90
3. 72
70
4. 49
50
5. 87
90
6. 33
30
7. 11
10
8. 44
40
9. 56
60
10. 3
0
11. 61
60
12. 65
70
13. 15
20
14. 85
90
15. 94
90
16. 39
40
17. 5
10
18. 1
0
Solve.
25 to 34 round to 30.
You can round up or round down.
19. Write six numbers that round to 30.
Explain.
55 to 64 round to 60.
You can round up or round down.
C – © CSL Associates, Inc. All rights reserved.
20. Write six numbers that round to 60.
Explain.
21. What number is halfway between 10 and 20?
22. What number is halfway between 340 and 350?
Math
Reasoning
15
345
Number Sense
MR 1.1
23. Round 303 to the nearest 10.
Explain.
303 rounds to 300.
3 is less than 5, so the ones round to 0.
Keep the other digits the same.
You can prove it by showing 303 on a number line.
Chapter 4 – Lesson 1
page 39
MCX94.HW.CL.G3.FM&Lesson.v211
8/3/04
13:56
Page 26
Name
…at home!
P RAC T I C E
Round each number to the nearest ten. You may use the chart.
1. 31
30
2. 1
0
3. 5
10
4. 59
60
5. 79
80
6. 35
40
7. 9
10
8. 33
30
9. 26
30
10. 2
0
11. 52
50
12. 85
90
13. 18
20
14. 75
80
15. 64
60
16. 29
30
17. 61
60
18. 31
30
Solve.
35 to 44 round to 40.
You can round up or round down.
19. Write six numbers that round to 40.
Explain.
65 to 74 round to 70.
You can round up or round down.
Explain.
21. What number is halfway between 20 and 30?
22. What number is halfway between 250 and 260?
Math
Reasoning
25
255
Number Sense
MR 1.1
23. Round 202 to the nearest 10.
Explain.
202 rounds to 200.
2 is less than 5, so the ones round to 0.
Keep the other digits the same.
You can prove it by showing 202 on a number line.
page 26
Home Resource and Homework
Chapter 4 Lesson 1
C – © CSL Associates, Inc. All rights reserved.
20. Write six numbers that round to 70.
MCX94TEG3Ch01_32.v8.9.3 2/21/01 14:44 Page 73
Name
P RAC T I C E
Round each number to the nearest ten. You may use the chart.
1. 21
20
2. 91
90
3. 72
70
4. 49
50
5. 87
90
6. 33
30
7. 11
10
8. 44
40
9. 56
60
10. 3
0
11. 61
60
12. 65
70
13. 15
20
14. 85
90
15. 94
90
16. 39
40
17. 5
10
18. 1
0
Solve.
25 to 34 round to 30.
You can round up or round down.
19. Write six numbers that round to 30.
Explain.
55 to 64 round to 60.
You can round up or round down.
C – © CSL Associates, Inc. All rights reserved.
20. Write six numbers that round to 60.
Explain.
21. What number is halfway between 10 and 20?
22. What number is halfway between 340 and 350?
Math
Reasoning
15
345
Number Sense
MR 1.1
23. Round 303 to the nearest 10.
Explain.
303 rounds down to 300.
3 is less than 5, so the ones round to 0.
Keep the other digits the same.
You can prove it by showing 303 on a number line.
Chapter 4 – Lesson 1
Student Book Page
page 39
Name
…at home!
P RAC T I C E
Round each number to the nearest ten. You may use the chart.
1. 31
30
2. 1
0
3. 5
10
4. 59
60
5. 79
80
6. 35
40
7. 9
10
8. 33
30
9. 26
30
10. 2
0
11. 52
50
12. 85
90
13. 18
20
14. 75
80
15. 64
60
16. 29
30
17. 61
60
18. 31
30
Solve.
35 to 44 round to 40.
You can round up or round down.
19. Write six numbers that round to 40.
Explain.
65 to 74 round to 70.
You can round up or round down.
Explain.
21. What number is halfway between 20 and 30?
22. What number is halfway between 250 and 260?
Math
Reasoning
25
255
Number Sense
MR 1.1
23. Round 202 to the nearest 10.
Explain.
202 rounds to 200.
2 is less than 5, so the ones round to 0.
Keep the other digits the same.
You can prove it by showing 202 on a number line.
page 26
Home Resource and Homework
Chapter 4 Lesson 1
C – © CSL Associates, Inc. All rights reserved.
20. Write six numbers that round to 70.