Numbers are classified into different types based on their properties.
Natural Numbers (ℕ)
Counting numbers starting from 1
Examples: 1, 2, 3, 4, 5, …
Whole Numbers
Natural numbers plus zero
Examples: 0, 1, 2, 3, …
Integers (ℤ)
Positive numbers, negative numbers, and zero
Examples: -5, -2, 0, 3, 8
Rational Numbers (ℚ)
Numbers that can be written as a fraction a/b
Decimals that terminate or repeat
Examples: 3/4, -2, 0.5, 0.333…
Irrational Numbers
Cannot be written as a fraction
Decimals do not terminate or repeat
Examples: √2, √5, π
2. Operations with Fractions (Criterion D)
Addition & Subtraction
Make denominators the same
Add or subtract the numerators
Example:
2/3 + 1/6
LCM of 3 and 6 = 6
= 4/6 + 1/6 = 5/6
Multiplication
Multiply numerators
Multiply denominators
Example:
3/4 × 2/5 = 6/20 = 3/10
Division
Flip the second fraction (reciprocal)
Then multiply
Example:
4/5 ÷ 2/3 = 4/5 × 3/2 = 12/10 = 6/5
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Patterns and Sequences
A pattern is a regular and repeated way in which numbers, shapes,
or objects change.
A sequence is an ordered list of numbers that follows a specific rule.
Sequences are important because they help us identify relationships,
predict future values, and describe mathematical rules.
Arithmetic and Geometric Sequences
A sequence is an ordered list of numbers that follows a clear rule.
Each number in the sequence is called a term.
The position of a term is represented by n.
The two most important types of sequences studied in MYP are:
Arithmetic sequences (add or subtract)
Geometric sequences (multiply or divide)
1. Arithmetic Sequences
An arithmetic sequence is a sequence in which the
difference between consecutive terms is constant.
This constant value is called the common difference, written as d.
Identifying an Arithmetic Sequence
To check whether a sequence is arithmetic:
Subtract consecutive terms
If the difference is the same each time, the sequence is arithmetic
Example:
7, 12, 17, 22, 27, …
12 − 7 = 5
17 − 12 = 5
Common difference, d = 5
Arithmetic sequences can be:
Increasing if d > 0
Decreasing if d < 0
2. Finding the nth Term of an Arithmetic Sequence
The general formula for the nth term of an arithmetic sequence is:
Tₙ = a + (n − 1)d
a = first term
d = common difference
n = term number
Worked Example
Find the nth term rule for the sequence:
4, 9, 14, 19, …
Step 1: Identify a and d First term, a = 4 Common difference, d = 5
Step 2: Substitute into the formula
Tₙ = 4 + (n − 1)5
Step 3: Simplify
Tₙ = 5n − 1
This rule allows us to find any term without listing the sequence.
3. Geometric Sequences
A geometric sequence is a sequence in which each term
is found by multiplying or dividing the previous term
by a constant value called the common ratio, written as r.
Identifying a Geometric Sequence
To check whether a sequence is geometric:
Divide consecutive terms
If the ratio is constant, the sequence is geometric
Example:
3, 6, 12, 24, 48, …
6 ÷ 3 = 2
12 ÷ 6 = 2
Common ratio, r = 2
4. Finding the nth Term of a Geometric Sequence
The general formula for the nth term of a geometric sequence is:
Tₙ = a × rⁿ⁻¹
a = first term
r = common ratio
n = term number
Worked Example
Find the nth term rule for the sequence:
5, 15, 45, 135, …
Step 1: Identify a and r a = 5 r = 3
Step 2: Substitute into the formula
Tₙ = 5 × 3ⁿ⁻¹
5. Arithmetic vs Geometric Sequences
Arithmetic sequences change by adding or subtracting
Geometric sequences change by multiplying or dividing
Arithmetic growth is linear
Geometric growth is exponential
6. Applying Sequences in Real-Life Situations
a) Arithmetic Sequence Example (Salary Increase)
A worker earns ₹30,000 in the first year.
Each year, their salary increases by ₹2,000.
This forms an arithmetic sequence:
30,000, 32,000, 34,000, 36,000, …
The nth-year salary can be found using:
Tₙ = 30000 + (n − 1)2000
b) Geometric Sequence Example (Population Growth)
A bacteria population doubles every hour.
The initial population is 500.
This forms a geometric sequence:
500, 1000, 2000, 4000, …
The population after n hours is:
Tₙ = 500 × 2ⁿ⁻¹
This model is used in science, finance, and economics.
3. BODMAS (Fractions & Decimals)
BODMAS shows the correct order of operations.
It tells us **which calculations to do first** to get the correct answer.
B – Brackets (solve inside brackets first)
O – Orders (powers and roots)
D – Division
M – Multiplication
A – Addition
S – Subtraction
⚠️ Division and multiplication are done from left to right.
Addition and subtraction are also done from left to right.
Example:
Workers ∝ 1 / Time
6 workers take 10 days
12 workers take = (6 × 10) ÷ 12 = 5 days
Identify whether the situation is direct or inverse before solving.
Practice Questions
Cost of 12 pens is ₹120. Find the cost of 1 pen (Direct Variation)
6 machines produce 120 units in 8 hours. How long will 4 machines take?
10 workers can complete a job in 15 days. Find time for 15 workers (Inverse Variation)
Identify if the following is direct or inverse: Speed ∝ Time to travel 100 km
Write an example of a direct variation in daily life
Graph Transformations
A transformation changes the position or orientation of a graph or shape
on the coordinate plane without changing its size or shape.
In MYP 2, we mainly study:
Translations
Reflections
Rotations
1. Translations on a Graph
A translation moves a graph from one place to another
without flipping, turning, or resizing it.
Every point moves the same distance in the
same direction.
Key idea: Translations change position only.
Translation Rule
A translation is written as:
(x, y) → (x + a, y + b)
a controls movement left or right
b controls movement up or down
Direction and Signs
Right → add to x
Left → subtract from x
Up → add to y
Down → subtract from y
Example: Translating a Point
Translate point A(2, 3) 4 units right and 1 unit down.
(x, y) → (x + 4, y − 1)
New point: A′(6, 2)
Translating a Shape
To translate a shape:
Write the coordinates of every vertex
Apply the translation rule to each point
Plot the new points
Join them in the same order
2. Reflections on a Graph
A reflection flips a graph across a line called the
mirror line.
The most common mirror lines are the x-axis and y-axis.
Reflection in the x-axis
The x-coordinate stays the same, but the y-coordinate changes sign.
(x, y) → (x, −y)
Reflection in the y-axis
The y-coordinate stays the same, but the x-coordinate changes sign.
(x, y) → (−x, y)
Example
Reflect point B(−3, 4) in the y-axis.
New point: B′(3, 4)
Important: Reflections reverse orientation (the shape looks flipped).
3. Rotations on a Graph
A rotation turns a graph around a fixed point called
the center of rotation.
In MYP 2, rotations are usually about the origin (0,0).
Common Rotations About the Origin
90° anticlockwise:(x, y) → (−y, x)
180° rotation:(x, y) → (−x, −y)
90° clockwise:(x, y) → (y, −x)
Example: 180° Rotation
Rotate point C(5, −2) by 180° about the origin.
New point: C′(−5, 2)
Rotations change orientation but keep
size and shape the same.
Summary Table
Translation: slide (position changes)
Reflection: flip (orientation reverses)
Rotation: turn around a point
5. Rates and Unit Rates
A rate compares two quantities with different units.
Speed = distance ÷ time
Cost per item
Unit Rate
Rate for one unit.
Example:
300 km in 5 hours
Speed = 300 ÷ 5 = 60 km/h
Practice Questions
A car travels 450 km in 9 hours. Find speed in km/h
Cost of 15 pens is ₹75. Find cost per pen
A person earns ₹1200 in 8 days. Find earnings per day
Water tank fills 180 liters in 3 minutes. Find liters per minute
Explain the difference between a rate and a unit rate
6. Percentages
Percentage means per hundred.
Example:
25% = 25/100 = 0.25
Percentage of a Quantity
20% of 150
= (20 ÷ 100) × 150
= 30
Practice Questions
Find 15% of 200
Convert 45% to a decimal
Calculate 30% of 500
Express 0.75 as a percentage
If 60 is 20% of a number, find the number
7. Percentage Increase and Decrease
Percentage Increase
Original price = ₹500
Increase = 10%
Increase amount = 10% of 500 = ₹50
New price = ₹550
Percentage Decrease
Original price = ₹800
Decrease = 15%
Decrease amount = 120
New price = ₹680
Always find the percentage change using the original value.
Practice Questions
Increase ₹400 by 12%
Decrease ₹600 by 20%
The price of an item increases from ₹250 to ₹300. Find the percentage increase
The price decreases from ₹500 to ₹425. Find the percentage decrease
Explain why percentage change is always calculated on the original value