CHAPTER 1 | WHOLE NUMBERS AND DECIMAL NUMBERS
Read the numbers in Problems 5 and 6 to your group and then to your class.
5.
6.
1.3
(a) 983,334
(b) 22,887
(c) 12,456,332
(d) 967
(e) 21,543,667,998
(f) $8,856,777,987
(g) $2,866
(h) $11,676,998
(i) $1,555,967
(a) 4,775,887,111
(b) 12,667
(c) 112,573
(d) 1,152,987
(e) 34,778,997
(f) $109,119,000
(g) $1,800
(h) $11,888,767,001
(i) $101
ROUNDING WHOLE NUMBERS
Sometimes it is easier to communicate an approximate value of a number rather than its exact value.
At these times, the number is rounded to its approximate value.
EXAMPLE
•
When describing the population of Canada, it may be appropriate to say or write
thirty-four million (34,000,000), rather than thirty-four million, four hundred
nine thousand, sixty-six (34,409,066).
•
When describing the profit of a company, it may be more appropriate to say or
write two million dollars ($2,000,000), rather than two million, one hundred
thirteen dollars ($2,000,113).
In this section, you will learn how to round whole numbers.
STEPS TO ROUND WHOLE NUMBERS
• Identify the digit to be rounded by underlining it.
• If the digit to the right of the underlined digit is:
• 5 or more than 5, then add 1 to the underlined digit.
• Less than 5, then do not add 1 to the underlined digit.
• Change all the digits to the right of the underlined digit to 0.
EXAMPLE
• Rounding 238 to the nearest ten is 240
• Rounding 154 to the nearest ten is 150
• Rounding 650 to the nearest hundred is 700
• Rounding 949 to the nearest hundred is 900
• Rounding 1,567 to the nearest thousand is 2,000
• Rounding $32 to the nearest $10 is $30
• Rounding $1,545 to the nearest $1,000 is $2,000
• Rounding 895 to the nearest ten is 900
• Rounding 997 to the nearest ten is 1,000
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1.3 ROUNDING WHOLE NUMBERS
EXERCISE 1.3
Answers to the odd numbered problems are available online
Round the numbers in Problems 1 to 4 to the place values specified in the brackets:
1.
(a) 500,022 (nearest thousand)
(b) 6,794 (nearest ten)
(c) 9,974,500,654 (nearest hundred million) (d) 4,556,475 (nearest ten)
2.
3.
4.
1.4
(e) 317,544 (nearest hundred thousand)
(f) 29,456 (nearest hundred)
(g) 245,999 (nearest ten thousand)
(h) 43,456,876,987 (nearest billion)
(i) 399,871,678 (nearest million)
(j) 58,552,499,899 (nearest ten million)
(a) 17,431,787,998 (nearest ten million)
(b) 9,432,347 (nearest ten)
(c) 12,374 (nearest hundred)
(d) 240,140 (nearest thousand)
(e) 145,986 (nearest hundred thousand)
(f) 24,978,333,126 (nearest billion)
(g) 129,123 (nearest ten thousand)
(h) 999,095,000 (nearest million)
(i) 1,273 (nearest ten)
(j) 9,900,997,999 (nearest hundred million)
(a) $22,500 (nearest $1,000)
(b) $9,900 (nearest $100)
(c) $154,999 (nearest $10,000)
(d) $171,040 (nearest $100,000)
(e) $9,101 (nearest $100)
(f) $1,349,995 (nearest $10)
(a) $5,354,534 (nearest $10)
(b) $563,957 (nearest $100,000)
(c) $491,867 (nearest $10,000)
(d) $7,346 (nearest $100)
(e) $6,546,998 (nearest $10)
(f) $14,564 (nearest $1,000)
5.
If the populations of Ontario and British Columbia last year were 13,118,756 and 4,456,883,
respectively, express each of these numbers rounded to the nearest million.
6.
Andrew’s website business made a profit of $22,457 last year. Express his profit rounded to the
nearest thousand dollars.
7.
Eddie and his wife travelled 3,586 km on their new bike. Express the distance travelled rounded
to the nearest hundred kilometres.
8.
The average distance between the Earth and the Moon is 384,410 km. Express this distance
rounded to the nearest hundred thousand km.
PLACE VALUE OF DECIMAL NUMBERS
The ‘place value’ or ‘position’ of a digit in a decimal number determines the value that the digit
represents in the decimal number.
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