1. COLEGIO SAN PATRICIO
Math Practice for 3rd Period Exam
School Year 2010 – 2011
Binary System
I. Convert each decimal number to the binary number it represents.
48 = 110000 104 = 1101000
II. Convert each binary number to the decimal number it represents.
1110010 = 114 10101 = 21

2. The Number Line
III. Write the missing numbers.
IV. Order the next numbers in the number line.
0 0.50 1 1½ 1.25 2
Verbal Phrases and Algebraic Expressions.
V. Answer the next problems.
Is it correct?
1. 2x + 6 = 12 CORRECT Two times a number, plus six is
twelve.
2. (5) (6) − x = 25 INCORRECT Five times the difference of six
5(6−x)=25 and a number is twenty five.
3. 8(4 + 9) = 104 CORRECT Eight times the sum of four and
nine is one hundred four.

3. VI. Write each as an algebraic expression.
1. The difference of 10 and 5 10−5
2. The quotient of 14 and 7 14÷7
3. u decreased by 17 u − 17
4. The product of x and 7 7x
5. Twice q 2q
Problem Solving Using Algebraic Equations.
VII. Solve.
1. If 2/3 of the pizza is left, what part will you and your two friends get?
A: for each. (You divide 2/3 by the 3 friends)
2. My brother will be forty years old in four years (I wrote forty instead of
four). Let b be the age of my brother now:
A: b) b+4 = 40, then you need to solve the equation. Do as follows:
Checking Process
b + 4 = 40 b + 4 = 40
b = 40 – 4 36 + 4 = 40
b = 36 40 = 40

4. 3. Donna got 84 in a quiz, which includes 5-point bonus. Let x be the
grade she would have had without the bonus.
A: c) x + 5 = 84, then you need to solve the equation. Do as follows:
Checking Process
x + 5 = 84 x+ 5 = 84
x = 84 – 5 79 + 5 = 84
x = 79 84 = 84
VIII. Write an equation.
1. I have to check 90 exams. I have checked 35. How many exams am I
missing?
A: Possible equation: x + 35 = 90 I am missing 55 exams
x = 90 – 35
x = 55
Checking Process:
x + 35 = 90
55 + 35 = 90
90 90
4. One trip is ¾ kms. If we decide to take 6 trips, how many kilometers
are we going to travel?
A: 4 ½ kms. (You multiply ¾ by the 6 trips)
Distributive Property.
1. Apply the Distributive Property.
1. −6(a+8) 2. 6(−5n+7) 3. (1+9x)(-4x) 4. 7m(m-9)
-6a – 48 - 30n + 42 -4x – 36x² 7m² - 63m

5. Combining Like Terms
2. Simplify the expression. (Order it, then combine like terms, and
simplify).
1.
-5c + 3c + 9 – 2
-2c + 7 (this is the answer)
2.
-4u² - u² + 10+8
-5u²+18 (this is the answer)
3.
7x + (8 – 4x)
7x + 8 – 4x
7x – 4x + 8
3x+8 (this is the answer)
Equations
3. Find the value of the variable.
1. 2. 3. 4.
40 - 30 = 10x a = 33/3 n=0+5 p = 20 + 20
10 = 10x a = 11 n=5 p = 40
10/10 = x
1=x
x=1
Checking Process Checking Process Checking Process Checking Process
40 = 10x + 30 3a = 33 -5 + n = 0 p – 20 = 20
40 = 10 (1) + 30 3(11) = 33 -5 + (5) = 0 40 – 20 = 20
40 = 10 + 30 33 = 33 -5 + 5 = 0 20 = 20
40 = 40 0=0
1. 20 5. 7. 8.
x/2 = 20 – 10 k = 10 (2) 2x – 4 = 6 x = 60/3
x/2 = 10 k = 20 2x = 6 + 4 x =20
x= 10(2) 2x = 10
x = 20 x= 10/2
x= 5

6. Checking Process Checking Process Checking Process Checking Process
x/2 + 10 = 20 k/2 = 10 3x – x - 4 = 6 3x =60
20/2 = 10 20/2 = 10 3(5) – 5 – 4 = 6 3(20) = 60
10 = 10 10 = 10 15 – 5 – 4 = 6 60 = 60
10 – 4 = 6
6=6
4. Solve using the integers rules.
1. 7- (+8) – 5 2. 45 (-5) + |6| 3. 4 + (-5) 4. 5 – (-5+8)
7–8–5 -225 + 6 4–5 5+5–8
-1 – 5 - 219 -1 10 – 8
-6 +2