Mathematics for the International Student - MYP 1 Comprehensive Study Notes

CHAPTER 1: NUMBER SYSTEMS

  • History of Counting and Tallying

    • Archaeologists and anthropologists suggest early counting used tallies (scratches on cave walls, knots on ropes, pebbles, or branch notches).

    • Transition to efficiency: Replacement of every 10 strokes with a symbol. For example, 23 in ancient Egypt was written as two symbols for 10 and three single strokes.

  • The Egyptian System (Base Ten)

    • Evidence dating back to 3600 BC.

    • Hieroglyphics: Sacred picture writings.

    • Symbols:

      • Staff: $1$

      • Hock: $10$

      • Scroll: $100$

      • Lotus flower: $1,000$

      • Bent stick: $10,000$

      • Burbay fish: $100,000$

      • Astonished man: $1,000,000$

      • Religious symbol: $10,000,000$

    • Additive system with no place value; order of symbols does not affect value.

  • Ancient Greek (Attic) System

    • Included symbols for 5 ($\Gamma$), 10 ($\Delta$), 100 ($H$), 1000 ($X$).

    • Combinations used for 50, 500, 5000 (e.g., combining 5 and 10 to make 50).

  • Roman Numerals

    • Symbols: $I=1$, $V=5$, $X=10$, $L=50$, $C=100$, $D=500$, $M=1,000$.

    • Rules:

      • Subtractive principle: $IV$ is 4 ($1$ before $5$), $VI$ is 6 ($1$ after $5$).

      • Restrictions: $I$ only before $V$ or $X$; $X$ only before $L$ or $C$; $C$ only before $D$ or $M$.

      • Large numbers: A stroke above a symbol makes it $1,000$ times larger (e.g., $\overline{V} = 5,000$).

  • The Mayan System

    • Used Base 20.

    • Vertically arranged symbols; place value above another.

    • Recognized a symbol for zero (looks like a mussel shell).

    • Symbols based on dots ($1$) and strokes ($5$).

  • Hindu-Arabic System

    • Developed in India 2000 years ago; introduced to Europe by Arab traders 1000 years ago.

    • Digits: $0, 1, 2, 3, 4, 5, 6, 7, 8, 9$.

    • Natural Numbers: Counting numbers (infinite set).

    • Whole Numbers: Natural numbers including zero.

    • Place Value: Units, Tens, Hundreds, Thousands, Ten Thousands, Hundred Thousands, Millions, etc.

    • Commas/Spaces: Used to separate groups of three digits (thousands, millions).

    • Large Definitions:

      • Million: $1,000,000$ (a $10 \text{ cm} \times 10 \text{ cm} \times 10 \text{ cm}$ cube contains $1,000,000 \text{ mm}^3$).

      • Billion: $1,000$ million ($1,000,000,000$).

      • Trillion: $1,000$ billion ($1,000,000,000,000$).

CHAPTER 2: OPERATIONS WITH WHOLE NUMBERS

  • Addition and Subtraction

    • Column method: Line up place values vertically.

    • Word Problems: Translate text into a mathematical sentence.

  • Multiplication and Division by Powers of 10

    • Powers of 10: $10, 100, 1000, \dots$

    • Multiplying: Add $n$ zeros or move point $n$ places right.

    • Dividing: Remove $n$ zeros or move point $n$ places left.

  • Multi-Step Problem Solving

    • Identify intermediate steps (e.g., find total cost before calculating change).

  • Number Lines

    • Represent order and relative positions. Arrowheads show infinite continuation.

    • Operations: Jump right for addition, left for subtraction.

  • Rounding and Estimation

    • Rounding Rule: If the digit after the rounding place is $\geq 5$, round up; otherwise, round down.

    • Significant Figures: The number of digits from the left that are important ($37,621 \approx 38,000$ to 2 sig figs).

    • One Figure Approximation: Round numbers to one significant figure to estimate products (e.g., $3,789 \times 6 \approx 4,000 \times 6 = 24,000$).

  • Estimation of Objects

    • Method: Divide area into equal parts, count one part, and multiply by total parts.

CHAPTER 3: POINTS, LINES AND ANGLES

  • Geometry Basics

    • Point: Marks a position; no size. Named with a capital letter.

    • Vertex: Corner point of a figure (plural: vertices).

    • Line: Continuous infinite collection of points $(AB)$.

    • Line Segment: Part of a line with two endpoints $[AB]$.

    • Ray: Starts at a point and continues infinitely $[AB)$.

    • Plane: A flat surface.

    • Parallel Lines ($k$): Fixed distance apart, never meet.

    • Intersecting Lines: Meet at a point of intersection.

  • Angles

    • Formed by two arms meeting at a vertex.

    • Units: Degrees ($^{\circ}$). Full turn = $360^{\circ}$.

    • Classification:

      • Acute: $0^{\circ} < x < 90^{\circ}$

      • Right: $90^{\circ}$

      • Obtuse: $90^{\circ} < x < 180^{\circ}$

      • Straight: $180^{\circ}$

      • Reflex: $180^{\circ} < x < 360^{\circ}$

      • Revolution: $360^{\circ}$

  • Angle Properties

    • Angles at a point: Sum to $360^{\circ}$.

    • Angles on a line: Sum to $180^{\circ}$.

    • Angles of a triangle: Sum to $180^{\circ}$.

    • Angles of a quadrilateral: Sum to $360^{\circ}$.

  • Bisecting Angles

    • Dividing an angle into two equal parts using a compass and ruler (construction).

CHAPTER 4: LOCATION

  • Map and Grid References

    • Used in directories/atlases to locate regions (e.g., D4, E5).

  • The Cartesian Plane

    • Origin: Intersection of axes at $(0, 0)$.

    • x-axis: Horizontal.

    • y-axis: Vertical.

    • Ordered Pairs: Coordinates $(x, y)$. x-coordinate first, then y-coordinate.

  • Interpreting Points

    • Axes are used for variables (e.g., age vs. height).

    • Variable: A quantity whose value can change.

  • Compass and Bearings

    • Cardinal Directions: North ($N$), South ($S$), East ($E$), West ($W$).

    • Ordinal Directions: $NE, SE, SW, NW$.

    • Compass Bearings: Starts with $N$ or $S$ and an acute angle (e.g., $N35^{\circ}E$).

    • True Bearings: Degrees clockwise from True North, always 3 digits (e.g., $072^{\circ}$, $320^{\circ}$).

CHAPTER 5: NUMBER PROPERTIES

  • Operations

    • Sum: Result of addition.

    • Difference: Result of subtraction.

    • Product: Result of multiplication.

    • Quotient: Result of division (Dividend $\div$ Divisor).

  • Zero and One

    • $n + 0 = n$; $n \times 0 = 0$; $n \div 0$ is undefined.

    • $n \times 1 = n$; $n \div 1 = n$.

  • Index Notation (Exponents)

    • $2^5 = 2 \times 2 \times 2 \times 2 \times 2$. Base ($2$), Index/Exponent ($5$).

  • Order of Operations (BEDMAS)

    • Brackets, Exponents, Division/Multiplication (left to right), Addition/Subtraction (left to right).

  • Square and Cube Numbers

    • Square: $n^2$ (e.g., $4^2 = 16$). Square root: $\sqrt{16} = 4$.

    • Cube: $n^3$ (e.g., $2^3 = 8$). Cube root: $\sqrt[3]{8} = 2$.

  • Factors and Multiples

    • Factors: Divide exactly into a number.

    • Prime: Exactly two factors ($1$ and itself).

    • Composite: More than two factors.

    • HCF: Highest Common Factor.

    • LCM: Lowest Common Multiple.

    • Divisibility Tests:

      • By 3: Sum of digits is divisible by 3.

      • By 4: Last two digits divisible by 4.

      • By 6: Divisible by both 2 and 3.

CHAPTER 6: FRACTIONS

  • Representation

    • Fraction $\frac{a}{b}$: $a$ is numerator, $b$ is denominator.

  • Equivalent (Equal) Fractions

    • Found by multiplying/dividing numerator and denominator by the same non-zero number.

    • Lowest Terms: Simplify by dividing by HCF.

  • Types of Fractions

    • Proper: Numerator $<$ Denominator.

    • Improper: Numerator $\geq$ Denominator (e.g., $\frac{5}{4}$).

    • Mixed Number: Whole number and fraction (e.g., $2\frac{2}{3}$). To convert: $2\frac{4}{5} = \frac{2 \times 5 + 4}{5} = \frac{14}{5}$.

  • Fractions of Quantities

    • "of" means multiply (e.g., $\frac{2}{3}$ of 24 = $\frac{2}{3} \times 24 = 16$).

  • Comparing Sizes

    • Convert to Lowest Common Denominator (LCD) to compare.

CHAPTER 7: POLYGONS

  • Classification

    • Closed straight-sided plane figures.

    • $n$-gon: Polygon with $n$ sides (e.g., Decagon = 10 sides).

    • Regular Polygon: All sides and angles are equal.

  • Triangles

    • Scalene: No equal sides.

    • Isosceles: Two equal sides; base angles opposite equal sides are equal.

    • Equilateral: Three equal sides; all angles are $60^{\circ}$.

  • Quadrilaterals

    • Parallelogram: Opposite sides parallel and equal.

    • Rectangle: Parallelogram with $90^{\circ}$ angles.

    • Rhombus: Quadrilateral with all sides equal.

    • Square: Rhombus with $90^{\circ}$ angles.

    • Trapezium: One pair of opposite sides parallel.

    • Kite: Two pairs of adjacent sides equal.

  • Euler’s Rule for Plane Figures

    • Connection between Vertices ($V$), Regions ($R$), and Edges ($E$):

    • E = V + R - 2

CHAPTER 8: FRACTION OPERATIONS

  • Addition and Subtraction

    • Change to common denominator, then add/subtract numerators.

    • Mixed numbers: Either convert to improper fractions first or add whole parts/fraction parts separately.

  • Multiplication

    • $\frac{a}{b} \times \frac{c}{d} = \frac{a \times c}{b \times d}$.

    • Cancellation: Cancel common factors before multiplying.

  • Reciprocals

    • Two numbers whose product is 1. Reciprocal of $\frac{a}{b}$ is $\frac{b}{a}$.

  • Division

    • Multiply by the reciprocal of the divisor: $\frac{a}{b} \div \frac{c}{d} = \frac{a}{b} \times \frac{d}{c}$.

CHAPTER 9: DECIMALS

  • Definition

    • Represent numbers between whole numbers. Tenths ($0.1$), hundredths ($0.01$), thousandths ($0.001$).

  • Operations

    • Add/Subtract: Align decimal points vertically.

    • Multiplication: Count total decimal places in question; answer should have the same total.

    • Division: Align point in answer directly above point in question.

  • Conversions

    • Decimal to Fraction: Value over its place value power of 10 ($0.72 = \frac{72}{100} = \frac{18}{25}$).

    • Terminating Decimals: Fractions whose denominators have only 2 or 5 as prime factors.

    • Recurring Decimals: Decimals that repeat a sequence (e.g., $\frac{1}{3} = 0.\overline{3}$).

  • Rounding Decimals: Similar to whole numbers, look at the next digit to decide whether to round up.

CHAPTER 10: PROBLEM SOLVING TECHNIQUES

  • Trial and Error: Guessing a solution and checking it, then adjusting.

  • Making a List: Systematically recording all possibilities.

  • Modelling/Drawing a Picture: Visualizing the physical scenario.

  • Making a Table/Looking for Pattern: Solving simpler versions and extending the rule.

  • Working Backwards: Using the final result and inverse operations to find the starting point.

CHAPTER 11 & 12: MEASUREMENT

  • Metric Length Units: $mm, cm, m, km$.

    • $1 \text{ cm} = 10 \text{ mm}$

    • $1 \text{ m} = 100 \text{ cm}$

    • $1 \text{ km} = 1000 \text{ m}$

  • Perimeter: Distance around a boundary.

    • Rectangle: $P = 2(length + width)$.

  • Scale Diagrams: Proportional drawings.

    • Real Length = Scale Length $\times$ Scale Factor.

  • Mass: Amount of matter (constant).

    • $1 \text{ g} = 1000 \text{ mg}$

    • $1 \text{ kg} = 1000 \text{ g}$

    • $1 \text{ t} = 1000 \text{ kg}$

  • Area: Amount of surface inside a boundary.

    • Rectangle: $A = l \times w$.

    • Triangle: $A = \frac{1}{2} \times base \times height$.

    • Units: $mm^2, cm^2, m^2, ha, km^2$. ($1 \text{ ha} = 10,000 \text{ m}^2$).

  • Volume: Amount of space occupied.

    • Prism: $Area of Base \times height$.

    • Units: $mm^3, cm^3, m^3$.

  • Capacity: Space inside a container (fluids).

    • $1 \text{ L} = 1000 \text{ mL} \approx 1000 \text{ cm}^3$.

    • $1 \text{ mL} \approx 1 \text{ cm}^3$.

CHAPTER 13: DIRECTED NUMBERS

  • Positives and Negatives

    • Used for opposites (Profit/Loss, Above/Below sea level).

    • Zero is neither positive nor negative.

  • Operations with Directed Numbers

    • Addition: Move right on number line.

    • Subtraction: Move left on number line.

  • Rules for Multiplication and Division:

    • $(+) \times (+) = (+)$

    • $(-) \times (-) = (+)$

    • $(+) \times (-) = (-)$

    • Same signs = Positive, Different signs = Negative.

  • Average: Sum of values $\div$ number of values (can be negative).

CHAPTER 14: PERCENTAGES

  • Definition: "Out of every hundred." $100% = 1$.

  • Conversions

    • To Percentage: Multiply by $100%$.

    • To Fraction/Decimal: Divide by $100%$.

  • Applications

    • Profit/Loss as %: $\frac{Profit/Loss}{Cost Price} \times 100%$.

    • Discount: Reduction from marked price.

    • Simple Interest: $Interest = \text{Percentage p.a.} \times \text{Principal} \times \text{Time}$.

CHAPTER 15: TIME AND TEMPERATURE

  • Conversions

    • $1 \text{ year} = 52 \text{ weeks} \approx 365 \text{ days}$.

    • $1 \text{ millennium} = 1000 \text{ years}$.

  • Time Formats

    • 12-hour: AM/PM.

    • 24-hour: Four digits ($2015$ hours = $8:15 \text{ pm}$).

  • Average Speed: $Average Speed = \frac{Distance}{Time}$.

  • Temperature:

    • Celsius ($^{\circ}C$): Water freezes at $0$, boils at $100$.

    • Fahrenheit ($^{\circ}F$): Water freezes at $32$, boils at $212$.

    • Formula: $F = 1.8 C + 32$.

CHAPTER 16-24: ADVANCED TOPICS

  • Statistics (Ch 17)

    • Population vs Sample.

    • Mode: Most frequent score.

    • Mean (Average): Total sum $\div$ count.

    • Graphs: Dot plots, Column graphs, Pie charts, Stem-and-leaf plots.

  • Algebra and Patterns (Ch 18 & 20)

    • Variables: Symbols representing numbers (e.g., $x$).

    • Equation: Two expressions equal to each other.

    • Inverse Operations: Used to solve equations (add/sub, mult/div).

  • Coordinates and Lines (Ch 21)

    • Cartesian plane with four quadrants.

    • Vertical Lines: $x = k$; Horizontal Lines: $y = k$.

  • Transformations (Ch 22)

    • Translation: Slide.

    • Reflection: Mirror image.

    • Rotation: Spin around a centre point.

    • Enlargement/Reduction: Change size by a scale factor.

    • Tessellation: Tiling with no gaps.

  • Sets (Ch 23)

    • Element ($\in$): Member of a set.

    • Intersection ($\cap$): Elements in both A and B.

    • Union ($\cup$): Elements in A or B.

    • Venn Diagram: Visual display of sets.

  • Solids (Ch 24)

    • Polyhedron: Flat-faced solids (Prisms, Pyramids).

    • Curved Solids: Sphere, Cylinder, Cone.

    • Net: 2D shape foldable into a 3D solid.