5.1 Rounding decimal #’s
I can round decimal numbers
Steps
1.
Underline the digit in the place to which you are rounding
2.
Draw a little curved arrow to the digit one place to the right
or
3.
Decide if that number is hefty (5 -9) or wimpy (0-4)
4.
If hefty, change the underlined digit to the next higher #
5.
If wimpy, leave the underlined digit alone
6.
Change ALL digits to the right of the underlined digit to zeros
7.
All digits to the left of the underlined number stay the same
8.
Remove any zeros at the right end of the number (optional)
Example
Round 4.329 to the nearest tenth.
1. 4.329
2. 4.329
3. the 2 in the hundredths place is a wimpy #
4. (skip this step)
5. the underlined digit remains the same
6. right #’s change to zeros:
.300
7. left end #’s stay same:
4.300
8. remove extra zeros:
4.3
Samples:
Round each number to the tenths place. (Show your work)
1) 23.467 __________
2)
475.89 _____________
3) 0.711 ___________
4) 1,256.1913 _____________
Round each number to the ones place. (Show your work)
5) 23.467 __________
6) 475.89 _____________
7) 0.711 __________
8) 1,256.1913 _____________
Round each number to the hundredths place. (Show your work)
9) 23.467 __________
10)
475.89 _____________
11) 0.711 ___________
12) 1,256.1913 _____________
Explain what happens when you round 9,999.999 to any place.
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In what real-world situation would you want to round a number?
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