(1) Calculation problem:
( 1)23+(-73)
(2)(-84)+(-49)
(3)7+(-2.04)
(4)4.23+(-7.57)
(5)(-7/3)+(-7/6)
(6)9/4+(-3/2)
(7)3.75+(2.25)+5/4
(8)-3.75+(+5/4)+(- 1.5)
(2) Calculate by a simple method:
( 1)(- 17/4)+(- 10/3)+(+ 13/3)+( 1 1/3)
(2)(- 1.8)+(+0.2)+(- 1.7)+(0. 1)+(+ 1.8)+(+ 1.4)
(3) It is known that X =+ 17 (3/4), Y =-9 (5/ 1 1) and Z =-2.25.
Find the value of: (-x)+(-y)+z.
Exercise 2 (Level B)
(1) calculation:
( 1)(+ 1.3)-(+ 17/7)
(2)(-2)-(+2/3)
(3)|(-7.2)-(-6.3)+( 1. 1)|
(4)|(-5/4)-(-3/4)|-| 1-5/4-|-3/4|)
(2) If |a|=4, |b|=2, and |a+b|=a+b, find the value of a-b.
Exercise 3 (Level A)
(1) Multiple choice questions:
The correct pronunciation of (1) formula -40-28+ 19-24+32 is ().
(a) minus 40, minus 28, plus 19, minus 24 and 32; (b) minus 40, minus 28 plus 19, minus 24 plus 32; (c) minus 40 minus 28 plus 19 minus 24 plus 32; (d) 40 minus 28 plus 19 minus 24.
(2) If the rational number A+B+C
(a) At least two of the three numbers are negative; (b) There is only one negative number in three numbers; (c) At least one of the three numbers is negative; (d) Two of the three numbers are positive or two are negative.
(3) If M
(A)0 (B) m (c) 2m (d)-2m
(4) In the following categories, the value that is not equal to X-y-Z is ()
(A)X-(Y-Z)(B)X-(Y+Z)(C)(X-Y)+(-Z)(D)(-Y)+(X-Z)
Exercise (4) (Level B)
(1) Calculation problem:
( 1)(-4)(+6)(-7)
(2)(-27)(-25)(-3)(-4)
(3)0.00 1*(-0. 1)*( 1. 1)
(4)24*(-5/4)*(- 12/ 15)*(-0. 12)
(5)(-3/2)(-4/3)(-5/4)(-6/5)(-7/6)(-8/7)
(6)(-24/7)( 1 1/8+7/3-3.75)*24
(2) Calculate by a simple method:
( 1)(-7 1/8)*(-23)-23*(-73/8)
(2)(-7/ 15)*(- 18)*(-45/ 14)
(3)(-2.2)*(+ 1.5)*(-7/ 1 1)*(-2/7)
(3) When a=-4, b=-3, c=-2, d=- 1, find the value of the algebraic expression (ab+cd)(ab-cd).
(4) Given1+2+3+...+31+32+33 =17 * 33, calculate the following formula.
The value of 1-3+2-6+3-9- 12+ ... +3 1-93+32-96+33-99.
Exercise 5 (Level A)
(1) Multiple choice questions:
(1) It is known that A and B are two rational numbers. If their quotient a/b=0, then ()
(A)a=0 and b≠0 (B)a=0 (C)a=0 or b=0 (D)a=0 or b≠0.
(2) Give the following four groups of numbers 1 and1; -1 and-1; 0 and 0; -2/3 and -3/2, where the reciprocal is ()
Only (a) only (b) only (c) only (d) both.
(3) If a/|b|(b≠0) is a positive integer, then ()
(A)|b| is a divisor of a (B)|b| is a multiple of a (C)a and B are the same symbol (D)a and B are different symbols.
(4) If a>b, then there must be ().
(A)A+b & gt； a(B)a-B & gt； a(C)2a & gt； ab(D)a/b & gt； 1