🦕 Dino Pre-Algebra Quiz

📚 Quick Concept Review!

Unit 1 • Place Value & Factors

🔢 Place Value & GCF / LCM

Each digit has a place: ones, tens, hundreds, thousands...
In 3,742: the 7 is in the hundreds place → value = 700

⭐ MEMORIZE THIS!

GCF = Greatest Common Factor (biggest number that divides both)
LCM = Least Common Multiple (smallest shared multiple)
GCF(12, 18) = 6 | LCM(4, 6) = 12

🦕 Example: GCF(12, 18)
12 = 2×2×3 | 18 = 2×3×3
Common factors: 2×3 = 6 ✓

Unit 2 • Prime Numbers

🔬 Prime Factorization

⭐ MEMORIZE THIS!

A prime number has only 2 factors: 1 and itself.
Primes: 2, 3, 5, 7, 11, 13, 17, 19, 23...

🦕 Example: 36 = 2 × 2 × 3 × 3 = 2² × 3²
Use a factor tree! Start dividing by the smallest prime.

Unit 3 • Fractions

🍕 Fractions

Adding: Same denominator → just add numerators! ¼ + ²⁄₄ = ¾
Multiplying: Multiply across! ²⁄₃ × ¾ = ⁶⁄₁₂ = ½

⭐ MEMORIZE THIS!

Add/Subtract: same denominator needed!
Multiply: top × top, bottom × bottom
Always simplify your answer!

Unit 4 • Decimals & Percents

💧 Decimals & 📊 Percentages

0.3 + 0.45 = 0.75 (line up decimal points!)
25% of 80 → 0.25 × 80 = 20

⭐ MEMORIZE THIS!

% → Decimal: divide by 100 | 25% = 0.25
% increase = (new − old) ÷ old × 100
50→60: (60−50)÷50×100 = 20%

Unit 5 • Integers & Order of Operations

❄️ Integers & 📐 PEMDAS

⭐ MEMORIZE THIS!

−5 + 8 = +3 (bigger absolute value wins!)
PEMDAS: Parentheses → Exponents → Multiply/Divide → Add/Subtract
3 + 4 × 2 = 3 + 8 = 11 (multiply FIRST!)

Unit 6 • Algebra Basics

🔠 Expressions, Equations & Inequalities

Evaluate: 2x + 5 when x = 3 → 2(3)+5 = 11
Solve: x + 7 = 15 → x = 15 − 7 = 8
Inequality: x − 3 > 4 → x > 7

⭐ MEMORIZE THIS!

Whatever you do to one side, do to the OTHER side too!
Inequality: flip the sign when multiplying/dividing by a NEGATIVE!

Unit 7 • Geometry & Data

🗺️ Ratios, Geometry & Data

Ratio 2:3 = 6:x → cross multiply → 2x = 18 → x = 9
Area of rectangle = length × width = 7 × 5 = 35
Area of triangle = ½ × base × height = ½ × 6 × 4 = 12
Mean = sum ÷ count → (4+6+8+10+12)÷5 = 8
Probability = favorable outcomes ÷ total = 1/6

🦖 Quiz Time! Choose Wisely!

1📍 PLACE VALUE

What is the value of the digit 7 in the number 3,742?

A) 7 B) 70 C) 700 D) 7,000

🦕 Answer: C) 700

In 3,742 → thousands=3, hundreds=7, tens=4, ones=2. The digit 7 is in the HUNDREDS place, so its value is 7 × 100 = 700. 🎉

2🧮 GCF

What is the Greatest Common Factor (GCF) of 12 and 18?

A) 2 B) 3 C) 6 D) 36

🦖 Answer: C) 6

Factors of 12: 1,2,3,4,6,12 | Factors of 18: 1,2,3,6,9,18
The largest factor in BOTH lists = 6. GCF(12,18) = 6 ✓

3🔬 PRIME FACTORIZATION

Which shows the prime factorization of 36?

A) 4 × 9 B) 2² × 3² C) 2 × 18 D) 6²

🦕 Answer: B) 2² × 3²

36 ÷ 2 = 18 → 18 ÷ 2 = 9 → 9 ÷ 3 = 3 → 3 ÷ 3 = 1
So 36 = 2 × 2 × 3 × 3 = 2² × 3². Only PRIME factors count! ✓

4🍕 FRACTIONS — ADDING

What is 1/4 + 2/4?

A) 3/8 B) 1/2 C) 3/4 D) 2/4

🦖 Answer: C) 3/4

Same denominator → just add numerators! 1 + 2 = 3, keep the 4.
1/4 + 2/4 = 3/4. (3/4 cannot be simplified further.) ✓

5🍕 FRACTIONS — MULTIPLYING

What is 2/3 × 3/4?

A) 5/7 B) 6/12 C) 1/2 D) 2/7

🦕 Answer: C) 1/2

Multiply across: (2×3)/(3×4) = 6/12 = 1/2 (simplified).
Note: B) 6/12 = 1/2, but C is the simplified final answer. ✓

6💧 DECIMALS

What is 0.3 + 0.45?

A) 0.48 B) 0.75 C) 0.078 D) 7.5

🦖 Answer: B) 0.75

Line up the decimal points!
0.30
+0.45
= 0.75
Think: 0.3 = 30 cents, 0.45 = 45 cents → 75 cents = 0.75 ✓

7📊 PERCENTAGES

What is 25% of 80?

A) 25 B) 40 C) 20 D) 2

🦕 Answer: C) 20

25% = 25/100 = 0.25 → 0.25 × 80 = 20
Shortcut: 25% = ¼ → 80 ÷ 4 = 20 ✓

8❄️ INTEGERS

What is −5 + 8?

A) −13 B) −3 C) 3 D) 13

🦖 Answer: C) 3

Different signs → subtract, keep the sign of the BIGGER number.
8 − 5 = 3, and 8 is positive, so answer = +3.
Think of a number line: start at −5, go RIGHT 8 steps → land on 3 ✓

9📐 ORDER OF OPERATIONS

Using PEMDAS, what is 3 + 4 × 2?

A) 14 B) 11 C) 10 D) 24

🦕 Answer: B) 11

PEMDAS: Multiply BEFORE adding!
Step 1: 4 × 2 = 8
Step 2: 3 + 8 = 11
If you added first (3+4=7, ×2=14) — that's WRONG! ✓

10🔠 EXPRESSIONS

Evaluate 2x + 5 when x = 3.

A) 8 B) 10 C) 11 D) 16

🦖 Answer: C) 11

Substitute x = 3: 2(3) + 5 = 6 + 5 = 11
Remember: 2x means 2 × x, not 2 + x! ✓

11⚖️ EQUATIONS

Solve for x: x + 7 = 15

A) x = 6 B) x = 8 C) x = 22 D) x = 9

🦕 Answer: B) x = 8

Subtract 7 from both sides: x + 7 − 7 = 15 − 7 → x = 8
Check: 8 + 7 = 15 ✓

12📏 INEQUALITIES

Which value of x satisfies x − 3 > 4?

A) x = 5 B) x = 7 C) x = 3 D) x = 8

🦖 Answer: D) x = 8

Add 3 to both sides: x > 4 + 3 → x > 7.
So x must be GREATER than 7. From the choices, only 8 > 7. ✓
Check: 8 − 3 = 5 > 4 ✓ | 7 − 3 = 4, NOT greater than 4 ✗

13⚡ RATIOS & PROPORTIONS

If the ratio is 2:3 and one part equals 6, what is the other part?
(i.e., 2/3 = 6/x)

A) 4 B) 6 C) 9 D) 12

🦕 Answer: C) 9

Cross multiply: 2/3 = 6/x → 2x = 3 × 6 = 18 → x = 18 ÷ 2 = 9
Check: 2/3 = 6/9 = 2/3 ✓

14🗺️ COORDINATE PLANE

What is the distance from the origin (0,0) to the point (3, 4)?

A) 7 B) 5 C) 12 D) 25

🦖 Answer: B) 5

Distance = √(x² + y²) = √(3² + 4²) = √(9 + 16) = √25 = 5
This is the famous 3-4-5 right triangle! 🔺 ✓

15📦 AREA — RECTANGLE

What is the area of a rectangle with length 7 and width 5?

A) 12 B) 24 C) 35 D) 70

🦕 Answer: C) 35

Area of rectangle = length × width = 7 × 5 = 35 square units ✓
(Perimeter would be 2×(7+5) = 24 — don't mix them up!)

16📐 AREA — TRIANGLE

What is the area of a triangle with base 6 and height 4?

A) 24 B) 10 C) 12 D) 20

🦖 Answer: C) 12

Area of triangle = ½ × base × height = ½ × 6 × 4 = 3 × 4 = 12 square units ✓
Always divide by 2 for triangles! 🔺

17🧮 LCM

What is the Least Common Multiple (LCM) of 4 and 6?

A) 2 B) 10 C) 24 D) 12

🦕 Answer: D) 12

Multiples of 4: 4, 8, 12, 16, 20...
Multiples of 6: 6, 12, 18, 24...
Smallest number in BOTH lists = 12 ✓

18📈 PERCENT INCREASE

A score went from 50 to 60. What is the percent increase?

A) 10% B) 15% C) 20% D) 25%

🦖 Answer: C) 20%

% increase = (New − Old) ÷ Old × 100
= (60 − 50) ÷ 50 × 100 = 10 ÷ 50 × 100 = 20% ✓
Common mistake: dividing by 60 (use the ORIGINAL number!)

19📊 STATISTICS — MEAN

What is the mean (average) of: 4, 6, 8, 10, 12?

A) 6 B) 8 C) 10 D) 40

🦕 Answer: B) 8

Mean = Sum ÷ Count
Sum: 4+6+8+10+12 = 40
Count: 5 numbers
Mean = 40 ÷ 5 = 8 ✓

20🎲 PROBABILITY

You roll a fair 6-sided die. What is the probability of rolling a 4?

A) 1/4 B) 4/6 C) 1/6 D) 1/3

🦖 Answer: C) 1/6

Probability = Favorable outcomes ÷ Total outcomes
Rolling a 4: only 1 way to get 4
Total sides: 6
P(4) = 1/6 ✓

Answer Key & Explanations

1. C) 700 — digit 7 is in hundreds place → 7×100=700

2. C) 6 — GCF(12,18): factors 12={1,2,3,4,6,12}, 18={1,2,3,6,9,18} → GCF=6

3. B) 2² × 3² — 36÷2=18, 18÷2=9, 9÷3=3, 3÷3=1 → 2×2×3×3=2²×3²

4. C) 3/4 — same denominator: 1+2=3 → 3/4

5. C) 1/2 — (2×3)/(3×4)=6/12=1/2

6. B) 0.75 — 0.30+0.45=0.75 (line up decimals)

7. C) 20 — 25%=0.25 → 0.25×80=20

8. C) 3 — different signs: 8−5=3, positive wins → +3

9. B) 11 — PEMDAS: 4×2=8 first, then 3+8=11

10. C) 11 — 2(3)+5=6+5=11

11. B) x=8 — x+7=15 → x=15−7=8 (check: 8+7=15 ✓)

12. D) x=8 — x−3>4 → x>7; only 8>7

13. C) 9 — 2/3=6/x → 2x=18 → x=9

14. B) 5 — √(3²+4²)=√(9+16)=√25=5 (3-4-5 triangle)

15. C) 35 — Area rectangle=l×w=7×5=35

16. C) 12 — Area triangle=½×6×4=12

17. D) 12 — Multiples of 4: 4,8,12... Multiples of 6: 6,12... LCM=12

18. C) 20% — (60−50)÷50×100=20%

19. B) 8 — Sum=40, Count=5, Mean=40÷5=8

20. C) 1/6 — 1 favorable ÷ 6 total = 1/6

🦕 Dino Pre-Algebra Quest!

🌿 What's Inside?

🔢 Place Value & GCF / LCM

🔬 Prime Factorization

🍕 Fractions

💧 Decimals & 📊 Percentages

❄️ Integers & 📐 PEMDAS

🔠 Expressions, Equations & Inequalities

🗺️ Ratios, Geometry & Data

Answer Key & Explanations

📋 Full Answer Review