PIX EDUCATION
內部資料，禁止外洩
Chapter 1
l Concept of Directed Numbers
1. If +100m means going 100m to the east, what do the following mean?
(a) +50 m
(b) -260 m
2. The passing mark of a test is 60 marks. A score of -x marks means the score is x marks below the
passing mark Represent each of the following scores by a rational number
(a)72 marks
(b)49 marks
(c)60 marks
3. The long jump standard distance in an athletic meet is 7 m. A record of +x m means that the
jumping distance is x m beyond the standard distance
(a) The distances achieved by Fred, Gary and Henry are recorded as +0.4 m, 0.3 m and -1.6 m
respectively. Find their actual long jump distances
(b) Between Gary and Henry, who has a better performance?
(c)The long jump world record made by Mike Powell in 1991 was 8.95 m. Write down this distance
using the recording format of the athletic meet mentioned above
l
Number line
1. Find the directed numbers represented by the letters on the number line below.
A:___________
B:___________
C:___________
D:___________
E:___________
2. Write down the following number on the number line
(a) -1,0,4,-5, 1.25,-2.5
3. Label the following numbers on the number line
(b) 10,50,-30,-25,60
F:___________
PIX EDUCATION
l
內部資料，禁止外洩
Opposite number & Absolute value
1. Write down the opposite number of each of the following
(a)The opposite number of 9 is _______
(b) The opposite number of-12 is ________
(c) The opposite number of-7 is ________
(d)The opposite number of 1.28 is ________
(e) The opposite number of 2.4 is ________ (f) The opposite number of-0.01 is ________
!
"
(g)The opposite number of is __________ (h) The opposite number of- is __________
"
#
2. Which of the following pairs of numbers are opposite numbers? Which of the following pairs of
numbers are equal?
(a) -(-9) and +(-9) are ____________
(b) -(+10) and +(-10) are ____________
(c) +(-25) and -(-25) are ___________
(d) +(+16) and -(-16) are ____________
3. Write down the absolute value of each of the following.
(a) |13|=________
(b) |-15|=________
$
(c) | |=________
!
%
(d) |- |=________
"
4. Determine whether each of the following is true or not.
(a) |-7|<|7|
(b) |-0.8|=|0.8|
(c) |-2|<0
(d) |-2.7|>0
5. Fill in the blanks
(a) The number(s) whose absolute value(s) equal to 7 is (are) __________________
(b)The number(s) whose absolute value(s) equal to 3.5 is (are) __________________
(c)The number(s) whose absolute value(s) equal to 0 is (are) __________________
!
(d)Is there any value whose absolute value equal to- ? __________________
"
6. Fill in the blanks with the signs ‘>’, ‘<’, or ‘=’
(a) |3.25| ______ |-2.1|
$
$
$'
(
(b) |- | ______ | |
(c) |-99|______|99|
(d) |0.05|______|-0.005|