Concept Review & Formula Bank

Master these key concepts before attempting the practice test. Each unit includes the essential formulas you must memorize and a worked example.

1
Number Theory & Properties
Unit 1

Number theory covers the fundamental properties of integers including divisibility, prime factorization, LCM, GCF, and number patterns.

🔑 Key Formulas & Rules

LCM(a, b) = (a × b) ÷ GCF(a, b)

Prime: divisible only by 1 and itself

Even × Odd = Even · Odd ± Odd = Even

Divisibility by 3: digit sum divisible by 3

Divisibility by 9: digit sum divisible by 9

📌 Must Memorize
  • Primes to 50: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47
  • Perfect squares: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100
  • A number is divisible by 4 if its last two digits are divisible by 4
✎ Worked Example
Find the GCF of 48 and 72.
✓ 48 = 2⁴ × 3 ; 72 = 2³ × 3² → GCF = 2³ × 3 = 24
2
Fractions, Decimals & Percents
Unit 2

Converting between fractions, decimals, and percents is essential. Know how to compare, order, and operate on all three forms.

🔑 Key Formulas & Rules

Percent = (Part ÷ Whole) × 100

Part = (Percent ÷ 100) × Whole

% Change = [(New − Old) ÷ Old] × 100

Fraction ÷ Fraction: multiply by reciprocal

📌 Must Memorize
  • 1/4 = 0.25 = 25% ; 1/3 ≈ 0.333 = 33.3% ; 1/5 = 0.2 = 20%
  • 3/4 = 0.75 = 75% ; 2/3 ≈ 0.667 = 66.7%
  • To find 15%: find 10%, then add half of that
✎ Worked Example
A shirt costs $40. After a 25% discount, what is the sale price?
✓ Discount = 25% × $40 = $10 → Sale price = $40 − $10 = $30
3
Ratios, Rates & Proportions
Unit 3

Ratios compare two quantities. Proportions set two ratios equal. Rates express a ratio with different units (e.g., miles per hour).

🔑 Key Formulas & Rules

Cross multiply: a/b = c/d → ad = bc

Distance = Rate × Time (D = R × T)

Unit rate = total ÷ number of units

Scale: actual = scale × map distance

📌 Must Memorize
  • If ratio of A:B = m:n, then A = mk and B = nk for some value k
  • Combined rate: if A does job in a hours, rate = 1/a per hour
  • Average speed = Total Distance ÷ Total Time
✎ Worked Example
A car travels 150 miles in 2.5 hours. What is its average speed?
✓ Speed = 150 ÷ 2.5 = 60 mph
4
Algebra — Expressions & Equations
Unit 4

Algebra involves using variables to represent unknown quantities. Solve equations by performing inverse operations on both sides.

🔑 Key Formulas & Rules

Distributive: a(b + c) = ab + ac

FOIL: (a+b)(c+d) = ac + ad + bc + bd

Difference of squares: a² − b² = (a+b)(a−b)

Quadratic formula: x = [−b ± √(b²−4ac)] / 2a

📌 Must Memorize
  • Solve for x: isolate x by adding/subtracting, then multiplying/dividing
  • Inequality: flip sign when multiplying/dividing by a negative number
  • (a + b)² = a² + 2ab + b² ; (a − b)² = a² − 2ab + b²
✎ Worked Example
Solve for x: 3(x − 4) = 2x + 5
✓ 3x − 12 = 2x + 5 → x = 17
5
Word Problems & Arithmetic
Unit 5

Translate English phrases into mathematical expressions. Identify the unknown, write an equation, and solve systematically.

🔑 Key Phrases to Know

"more than" → add (+)

"less than / fewer" → subtract (−)

"of" (with percent) → multiply (×)

"per" → divide (÷) or rate

"consecutive integers" → n, n+1, n+2, ...

📌 Must Memorize
  • Simple interest: I = P × r × t
  • Mixture problems: quantity × concentration = amount of substance
  • Age problems: use a variable, express all ages in terms of it
✎ Worked Example
The sum of three consecutive even integers is 78. Find the largest.
✓ n + (n+2) + (n+4) = 78 → 3n + 6 = 78 → n = 24. Largest = 28.
6
Geometry — Plane & Solid Figures
Unit 6

Know area, perimeter, and volume formulas. Understand properties of triangles, circles, quadrilaterals, and 3-D shapes.

🔑 Key Formulas

Triangle: A = ½bh ; Pythagorean: a²+b²=c²

Circle: A = πr² ; C = 2πr

Rectangle: A = lw ; P = 2(l+w)

Trapezoid: A = ½(b₁+b₂)h

Cylinder: V = πr²h ; Cube: V = s³

📌 Must Memorize
  • Triangle angles sum = 180° ; Quadrilateral = 360°
  • Common Pythagorean triples: 3-4-5, 5-12-13, 8-15-17
  • 30-60-90: sides = x : x√3 : 2x ; 45-45-90: x : x : x√2
✎ Worked Example
A circle has a radius of 7. What is its area? (Use π ≈ 22/7)
✓ A = πr² = (22/7) × 49 = 154 square units
7
Data Analysis — Mean, Median, Mode
Unit 7

Analyze data sets using statistical measures. Interpret graphs, charts, and tables accurately.

🔑 Key Formulas

Mean = Sum of values ÷ Number of values

Median = middle value when ordered

Mode = most frequently occurring value

Range = Maximum − Minimum

Probability = Favorable ÷ Total outcomes

📌 Must Memorize
  • For even number of data: median = mean of two middle values
  • Outliers affect mean more than median
  • Weighted average: (sum of weight × value) ÷ total weight
✎ Worked Example
Scores: 72, 85, 90, 68, 95. Find the mean.
✓ Mean = (72+85+90+68+95) ÷ 5 = 410 ÷ 5 = 82
8
Patterns, Functions & Sequences
Unit 8

Identify arithmetic and geometric sequences, find nth terms, and recognize functional relationships.

🔑 Key Formulas

Arithmetic: aₙ = a₁ + (n−1)d

Arithmetic sum: Sₙ = n(a₁+aₙ)/2

Geometric: aₙ = a₁ × rⁿ⁻¹

Function notation: f(x) = expression

📌 Must Memorize
  • Common difference (d) in arithmetic sequence is constant
  • Common ratio (r) in geometric sequence is constant
  • f(x) = 2x + 3 means: substitute x, multiply by 2, add 3
✎ Worked Example
Find the 10th term of the arithmetic sequence: 3, 7, 11, 15, ...
✓ d = 4, a₁ = 3 → a₁₀ = 3 + (9)(4) = 3 + 36 = 39
✏️

SSAT Mathematics Practice Test

20 questions · 5 choices each · Select your answer — feedback appears immediately