Download How to Round Numbers - Elgin Local Schools

Rounding
* My goal is… to __________ whole numbers and decimals to any given place.
What is "Rounding" ?
Rounding means _________________________in a number, while trying to keep its value __________.
Ex: 73 rounded to the nearest ten is 70, because 73 is closer to 70 than to 80.
How to Round Numbers
• Decide which is the last digit to keep
• Leave it the same if the next digit is less than 5 (this is called rounding ____________)
• But increase it by 1 if the next digit is 5 or more (this is called rounding ________)
Remember- “5 or above, _________________________________________.
4 or below, __________________________________________.”
Poduch’s Recommendation:
1.)
2.)
3.)
4.)
Underline the place that you are rounding to.
Use a line to “cut” the number after the place you are rounding to.
If the first “cut” digit is a 5 or higher, round up by one.
Rewrite the rounded number, stopping at the correct place.
Examples:
1.)
3.14159
2.)
2.456
3.)
109.61
4.)
154.999
rounded hundredths is: __________________
rounded tenths is: __________________
rounded whole (ones place) is: __________________
rounded tens is: __________________
Story Problems:
5.) For Cathy’s wedding, she thinks that 172 guests will come. Her party planner asks for her
to estimate how many people will be at the wedding, so Cathy rounds to the nearest tens.
What number does Cathy give the party planner?
6.) Mangos are $1.19 per pound. Destin’s bag of mangos weighs 3.2 pounds. How much will
the bag of mangos cost?
7.) Cory is ordering rope to make a tree-swing. He measures the length as 18.95 feet. The
company asks him to round the measurement to the nearest tenth of a foot. How much
rope will he order?
Math HW
Rounding
Name: _____________________________
Date: ______________________________
Period: ___________________
My GOAL is to successfully round whole numbers and decimals to any given place.
Math
HW #7
Story Problem:
1. Ron and Amanda collected 497 buttons, but lost 177 of them after dropping some. About how many buttons
do they have now? Choose the best estimate. All choices are rounded to the nearest hundred.
A: 500
C: 300
B: 400
D: 100
2. Dani’s cheer squad has 27 chants that they know. Dani creates 12 more to teach them. About how many
chants does the team know now? All choices are rounded to the nearest ten.
A: 50
C: 30
B: 40
D: 20
3. Potatoes are $2.86 per pound. If Wyatt buys 4.2 pounds of potatoes, how much money will it cost?
Remember: money is always rounded to the nearest hundredth.