Download - Rounding Decimal Numbers
Rounding Decimal Numbers
Grade 6 Unit NSN
Re-cap… What is a place value chart? What are the periods in the place value
chart? What are the greater than and less than
symbols?
What does it mean to round a number?
What does it mean to estimate?
Molly has $16 in her pocket
She buys:
•3 hotdogs @ $1.89 each
•3 milkshakes @ $2.19 each
•3 Large French fries @ $ $1.79 each
Does she have enough money?
Gas costs $1.79 per gallon
I’m running on empty and I have a 20 gallon tank on my truck……
About how much will it cost to fill up?
You have one hour to take a 50 question test.
About how much time can you spend on each question?
The Rounding Poem
Find your number
Look right next door
4 or less, just ignore
5 or more add one more!
Rounding Whole Numbers
Round 474 to the closest hundred.
474 Find your numberLook right next door
Four or less, just ignore
Five or more, add one more
474 Rounded to the hundreds becomes 500
Round 474 to the closest 10’s
474
Just ignore - 470
Try These•4,215
•394
•27
•127,591
•638
What about decimal numbers
The same rules (and poem) apply!Round 4.167 to the closest hundredths
4.167 Find your number
Look right next door
4.17
RememberIf you are asked to round to the nearest tenth…….your
answer stops at the tenth place!
Example: Round 42.73 to the closest tenth would be 42.7
Special Case!Rounding a 9
Round 2.197 to the closes hundredths
Since there is a “9” in the hundredths place consider the tenth and hundredths together – 19 – do you leave it at 19 or move it to 20?
Round 4.95 to the closest tenth
Since there is a “9” in the tenth spot consider the ones and tenths together…… should you leave it at 49 or move it to 50?
4.95 rounded to the nearest tenth is 5.0
Try these
Round to tenths:
4.56 4.6
5.32 5.3
0.98 1.0
Round to hundredths
18.784 18.78
9.456 9.46
9.997 10.00