unit 2 lesson 7 part 2: rounding to the nearest hundred copyright © 2009 kelly mott
TRANSCRIPT
Unit 2 Lesson 7 Part 2: Rounding to the Nearest Hundred
Copyright © 2009 Kelly Mott
Unit 2 Lesson 7 Part 2: Rounding to the Nearest Hundred
Copyright © 2009 Kelly Mott
Part 1: Understanding Rounding
Copyright © 2009 Kelly Mott
• Rounding is a way to estimate or tell about how many.
• Rounding does not give an exact amount.
Copyright © 2009 Kelly Mott
What is Rounding?
How many marbles
are in the jar?
Answer: There are about 200 marbles in the jar.
Whenever you see the word:
THAT MEANS THE ANSWER WAS ROUNDED!
Copyright © 2009 Kelly Mott
What is Rounding?
WHEN WE ROUND WE TELL:
Copyright © 2009 Kelly Mott
Rounding
Part 2: Rounding with a Number Line
Copyright © 2009 Kelly Mott
What is 130 rounded to the nearest hundred?• Find 130 on the number line. Put a dot.• Is 130 closer to 100 or 200? _______________• Answer: 130 rounded to the nearest hundred is
_____________________
100 110 120 130 140 150 160 170 180 190 200
Copyright © 2009 Kelly Mott
Round to the Nearest Hundred
What is 180 rounded to the nearest hundred?• Find 180 on the number line. Put a dot.• Is 180 closer to 100 or 200? _______________• Answer: 180 rounded to the nearest hundred is
_____________________
100 110 120 130 140 150 160 170 180 190 200
Copyright © 2009 Kelly Mott
Round to the Nearest Hundred
What is 150 rounded to the nearest hundred?• Find 150 on the number line. Put a dot.• Is 150 closer to 100 or 200? _______________• Answer: 150 rounded to the nearest hundred is
_____________________
100 110 120 130 140 150 160 170 180 190 200
Copyright © 2009 Kelly Mott
Round to the Nearest Hundred
*Hint: When we have 5 or more, we round up.
Copyright © 2009 Kelly Mott
Copyright © 2009 Kelly Mott
What is 340 rounded to the nearest hundred?• Find 340 on the number line. Put a dot.• Is 340 closer to 300 or 400? _______________• Answer: 340 rounded to the nearest hundred is
_____________________
300 310 320 330 340 350 360 370 380 390 400
Copyright © 2009 Kelly Mott
Round to the Nearest Hundred
What is 670 rounded to the nearest hundred?• Find 670 on the number line. Put a dot.• Is 670 closer to 600 or 700? _______________• Answer: 670 rounded to the nearest hundred is
_____________________
600 610 620 630 640 650 660 670 680 690 700
Copyright © 2009 Kelly Mott
Round to the Nearest Hundred
What is 450 rounded to the nearest hundred?• Find 450 on the number line. Put a dot.• Is 450 closer to 400 or 500? _______________• Answer: 450 rounded to the nearest hundred is
_____________________
400 410 420 430 440 450 460 470 480 490 500
Copyright © 2009 Kelly Mott
Round to the Nearest Hundred
*Hint: When we have 5 or more, we round up.
Copyright © 2009 Kelly Mott
Part 3: Rounding without a Number Line
Copyright © 2009 Kelly Mott
Steps to Round a Number:STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
260
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Practice # 1STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
419
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Practice # 2STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
608
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Practice # 3STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
577
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Practice # 4STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
825
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Practice # 5STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
139
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Practice # 6STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
765
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Practice # 7STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
941
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Practice # 8STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
289
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Practice # 9STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
573
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Practice # 10STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
610
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Practice # 11STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
276
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Practice # 12STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
459
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Practice # 13STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
125
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Practice # 14STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
708
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Practice # 15STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
672
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Practice # 16STEPS:1. Underline the place you are
rounding to.2. Circle the number to the right.
3. If the number to the right is 0, 1, 2, 3, or 4, then the underlined number stays the same.
4. If the number to the right is 5, 6, 7, 8, or 9, then the underlined number needs to go up 1 more number.
5. Every number to the right of the underlined number becomes a zero.
Copyright © 2009 Kelly Mott
Round to the nearest hundred:
880
Hint for the Circled Number:4 or less just ignore.5 or more, add 1 more.
Copyright © 2009 Kelly Mott
Does this make sense?
Copyright © 2009 Kelly Mott
HOMEWORKTeacher Worksheet: Rounding to Nearest Hundred WorksheetMath Steps Pages: noneRe-teach Page: none
Copyright © 2009 Kelly Mott
You can use the Rounding Pyramid:
51
2
84
0
93
76
1. Underlined number rounds up one
2. Add the zeros
1. Underlined number stays the same
2. Add the zeros
Copyright © 2009 Kelly Mott