6.2a Arithmetic & Comparison Operators — Edexcel 1CP2

Arithmetic Operators

Arithmetic operators perform mathematical calculations. Python supports all standard maths operations:

Operator	Name	Example	Result
`+`	Addition	`7 + 3`	10
`-`	Subtraction	`7 - 3`	4
`*`	Multiplication	`7 * 3`	21
`/`	Division (float result)	`7 / 2`	3.5
`//`	Integer division (DIV)	`7 // 2`	3
`%`	Modulus / remainder (MOD)	`7 % 2`	1
`**`	Exponentiation (power)	`2 ** 8`	256

DIV and MOD — key operators for Edexcel

DIV (//): Integer division — divides and discards the remainder (floor division)

MOD (%): Gives the remainder after division. Very useful for:

Checking if a number is even: n % 2 == 0
Checking if a number is divisible by something: n % 5 == 0
Extracting digits: n % 10 gives the units digit

# DIV and MOD examples
print(17 // 5)  # 3 (17 divided by 5 = 3 remainder 2, DIV gives 3)
print(17 % 5)   # 2 (17 divided by 5 = 3 remainder 2, MOD gives 2)
print(8 % 2)    # 0 (8 is divisible by 2, so remainder is 0 = even)
print(7 % 2)    # 1 (7 is odd, remainder = 1)

Operator Precedence (BIDMAS)

Python follows BIDMAS/BODMAS order:

Brackets () — highest priority
Indices (Exponentiation) **
Division / and Multiplication * (equal priority, left to right)
Addition + and Subtraction - (lowest)

print(2 + 3 * 4)     # 14, not 20 — multiply before add
print((2 + 3) * 4)   # 20 — brackets first
print(2 ** 3 + 1)    # 9 — exponent before add: 8+1=9

Comparison Operators

Comparison operators compare two values and return a Boolean (True or False). Used in if statements and while conditions:

Operator	Meaning	Example	Result
`==`	Equal to	`5 == 5`	True
`!=`	Not equal to	`5 != 3`	True
`>`	Greater than	`7 > 3`	True
`<`	Less than	`3 < 7`	True
`>=`	Greater than or equal to	`5 >= 5`	True
`<=`	Less than or equal to	`4 <= 3`	False

# Comparison examples
score = 65
print(score >= 60)   # True
print(score == 100)  # False
print(score != 0)    # True

# In conditions
if score >= 50:
    print("Pass")

Assignment Operators

Shorthand operators for updating variables:

Operator	Example	Equivalent to
`+=`	`x += 5`	`x = x + 5`
`-=`	`x -= 3`	`x = x - 3`
`*=`	`x *= 2`	`x = x * 2`
`//=`	`x //= 2`	`x = x // 2`

Exam tip: The % (modulo) and // (integer division) operators come up very often in Edexcel exams. Know that x % 2 == 0 checks for even numbers. Know that 17 // 5 = 3 and 17 % 5 = 2 (because 5×3=15, remainder 2).

⚠️ Common Mistakes

Using = (assignment) instead of == (equality check) in a condition
Thinking 7 / 2 = 3 — in Python 3, / always gives a float (3.5). Use // for integer division
Getting BIDMAS wrong — 2 + 3 * 4 = 14, not 20
In Edexcel pseudocode: DIV is written as DIV and MOD as MOD, not // or %

▶

Video coming soon

Click slide or press arrow keys to navigate

✍️

Worksheet — 6.2a Operators

8 Edexcel-style questions · instantly marked

Q1State the result of each expression: (a) 20 // 3 (b) 20 % 3 (c) 2 ** 4 (d) 15 / 4[4]

✅ Mark scheme

(a) 6 [1]; (b) 2 [1]; (c) 16 [1]; (d) 3.75 [1]. Note: 20 ÷ 3 = 6 remainder 2, so DIV=6, MOD=2. 2**4 = 2×2×2×2 = 16. 15/4 = 3.75 (float division in Python 3).

Q2What is the output of: print(2 + 3 * 4 - 1) ? Show your working.[2]

✅ Mark scheme

13 [1]; Working: multiplication first: 3*4=12, then left to right: 2+12=14, 14-1=13 [1].

Q3Write Python code to check if a number stored in a variable n is divisible by both 3 and 5 (i.e., divisible by 15).[2]

✅ Mark scheme

if n % 3 == 0 and n % 5 == 0: [2] (award 1 mark for n % 15 == 0 as an alternative). Must use == not =.

Q4Explain the difference between / and // in Python. Give an example of each.[4]

✅ Mark scheme

/ performs regular division and always returns a float [1]; e.g. 7 / 2 = 3.5 [1]; // performs integer (floor) division — divides and discards the remainder, returning an integer [1]; e.g. 7 // 2 = 3 [1].

Q5A program stores a time in total seconds. Write Python code to display it as minutes and seconds (e.g. 125 seconds = 2 mins 5 secs).[3]

✅ Mark scheme

total = 125 (or any variable) [accept if already declared]; minutes = total // 60 [1]; seconds = total % 60 [1]; print(str(minutes) + " mins " + str(seconds) + " secs") or equivalent [1].

Q6Evaluate each comparison and state True or False: (a) 10 != 10 (b) 7 >= 7 (c) 3 < 3 (d) 5 == 5.0[4]

✅ Mark scheme

(a) False [1]; (b) True [1]; (c) False — 3 is not strictly less than 3 [1]; (d) True — Python considers integer 5 equal to float 5.0 [1].

Q7A student writes: if age = 18: print("adult"). Identify the error and correct it.[2]

✅ Mark scheme

Error: = is the assignment operator, not a comparison operator [1]; Correction: if age == 18: — must use double equals == to compare [1].

Q8In Edexcel pseudocode, what symbols are used for: (a) integer division, (b) modulus/remainder, (c) not equal to?[3]

✅ Mark scheme

(a) DIV [1]; (b) MOD [1]; (c) ≠ or != [1] — Edexcel uses DIV and MOD as keywords in pseudocode rather than // and %.

Topic Quiz

Q 1 of 15

You scored

out of 15

Click to reveal definition

🎉

Session complete!

Term	Definition

🔒

Unlock Pro

Subscribe to access all 59 Edexcel 1CP2 lessons.

£7.99/month

or £59/year

Arithmetic Operators

DIV and MOD — key operators for Edexcel

Operator Precedence (BIDMAS)

Comparison Operators

Assignment Operators

Worksheet — 6.2a Operators

Mini Test — Operators

Unlock Pro