Order of operations with brackets in Python
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Which line correctly finds the average of a and b?
2. What does this print?
print(2 + 3 * 4)
3. What does this print?
print((2 + 3) * 4)
4. Which statement about Python's order of operations is true?
5. A student wants the average of three marks. Which line is correct?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1(a + b) / 2 | AThe brackets are missing, so only b is divided by 2. It should be average = (a + b) / 2. | |
| 2a + b / 2 | BDivides b by 2 first, then adds a, so it does not give the average of a and b | |
| 3Brackets are worked out first, so they can force an addition to happen before a multiplication | CAdds a and b first because of the brackets, then divides the total by 2 to find the average | |
| 4Python works out ** before * / // % and before + -, so the power is calculated first | DThree values are added but divided by 2. The total should be divided by 3 to find the average of three numbers. | |
| 5average = a + b / 2 | Eresult = 2 + 3 ** 2 | |
| 6average = (a + b + c) / 2 | Ftotal = (3 + 4) * 2 |
C
Definitions
(a + b) / 2
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
average = (a + b) _ 2
2.
total = (5 + 3) _ 2
print(total)
3.
avg = (m1 + m2 + m3) / _
4.
print(_2 + 3) * 4)
5.
print((2 + 3) __ 2)
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
a, b = 80, 90
B
average = a + b / 2
C
print(average)
Question 2
A
total = 5 + 3 * 2
B
print(total)
C
print(total == 16)
Question 3
A
english = 70
B
maths = 90
C
average = english + maths / 2
D
print(average)
Question 4
A
square = 3 + 2 ** 2
B
print(square)
C
print(square == 25)
Question 5
A
ticket = 12
B
total = ticket + 3 * 4
C
print("Total:", total)
Answer Key
Order of operations with brackets in Python
Section A: Quick Questions
Q1
A — average = (a + b) / 2
Q2
A — 14
Q3
B — 20
Q4
A — Brackets are worked out before **, * and /
Q5
B — avg = (m1 + m2 + m3) / 3
Section B: Match the Pairs
Q1
(a + b) / 2 → Adds a and b first because of the brackets, then divides the total by 2 to find the average
Q2
a + b / 2 → Divides b by 2 first, then adds a, so it does not give the average of a and b
Q3
Brackets are worked out first, so they can force an addition to happen before a multiplication → total = (3 + 4) * 2
Q4
Python works out ** before * / // % and before + -, so the power is calculated first → result = 2 + 3 ** 2
Q5
average = a + b / 2 → The brackets are missing, so only b is divided by 2. It should be average = (a + b) / 2.
Q6
average = (a + b + c) / 2 → Three values are added but divided by 2. The total should be divided by 3 to find the average of three numbers.
Section C: Definitions
Q1
(a + b) / 2 — Python works out brackets first, so (a + b) / 2 adds a and b before dividing by 2. Without the brackets, the division would happen first and the average would be wrong.Section D: Fill in the Blanks
Q1
average = (a + b) / 2Q2
total = (5 + 3) * 2
print(total)Q3
avg = (m1 + m2 + m3) / 3Q4
print((2 + 3) * 4)Q5
print((2 + 3) ** 2)Section E: Spot the Error
Q1
B — Without brackets, Python divides b by 2 first and then adds a, so the result is 125.0, not 85.0. It should be average = (a + b) / 2.
Q2
A — Multiplication happens before addition, so this gives 11, not 16. Brackets are needed to add first: total = (5 + 3) * 2.
Q3
C — Division is done before addition, so only maths is halved and the result is 115.0. It should be average = (english + maths) / 2.
Q4
A — The ** operator runs before +, so this calculates 3 + 4 = 7. Brackets are needed to add first: square = (3 + 2) ** 2 gives 25.
Q5
B — Multiplication happens first, so this gives 12 + 12 = 24, not 60. Brackets are needed: total = (ticket + 3) * 4.