114 Chapter 1 Whole Numbers
When we don’t need exact results, we often
roundnumbers.
Rounding a Whole Number
- To round a number to a certain place
value, locate the rounding digitin that
place. - Look at the test digit,which is directly to
the right of the rounding digit. - If the test digit is 5 or greater, round up by
adding 1 to the rounding digit and
replacing all of the digits to its right with 0.
If the test digit is less than 5, replace it and all
of the digits to its right with 0.
Round 9,842 to the nearest ten.
Rounding digit: tens column
9,842
Test digit: Since 2 is less than 5, leave the rounding digit
unchanged and replace the test digit with 0.
Thus, 9,842 rounded to the nearest ten is 9,840.
Round 63,179 to the nearest hundred.
Rounding digit: hundreds column
63,179
Test digit: Since 7 is 5 or greater, add 1 to the rounding digit and
replace all the digits to its right with 0.
Thus, 63,179 rounded to the nearest hundred is 63,200.
Whole numbers are often used in tables, bar
graphs,and line graphs.
See page 9 for an example of a table, a bar graph, and a line graph.
REVIEW EXERCISES
Consider the number 41,948,365,720.
- Which digit is in the ten thousands column?
- Which digit is in the hundreds column?
- What is the place value of the digit 1?
- Which digit tells the number of millions?
- Write each number in words.
a. 97,283
b. 5,444,060,017 - Write each number in standard form.
a. Three thousand, two hundred seven
b. Twenty-three million, two hundred fifty-three
thousand, four hundred twelve
Write each number in expanded form.
7. 570,302
8. 37,309,154
Graph the following numbers on a number line.
- 0, 2, 8, 10
0 1 2 3 4 56 789 10
0 1 2 3 4 56 789 10
- the whole numbers between 3 and 7
13. Round 2,507,348
a. to the nearest hundred
b. to the nearest ten thousand
c. to the nearest ten
d. to the nearest million
14. Round 969,501
a. to the nearest thousand
b. to the nearest hundred thousand
15. CONSTRUCTION The following table lists the
number of building permits issued in the city of
Springsville for the period 2001–2008.
Year 2001 2002 2003 2004 2005 2006 2007 2008
Building 12 13 10 7 9 14 6 5
permits
Place an or an symbol in the box to make a true
statement.
- 9 7 12.301 310
a. Construct a bar graph of the data.
5
10
15
Permits issued
Year
Bar graph
2001 2002 2003 20042005 2006 20072008