Runtime error: type mismatch
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. What happens when Python runs: print('5' + 3)?
2. age = input('Age: ')
print(age + 1)
Why does this crash?
3. Which line correctly fixes the crash when adding 1 to the user's typed age?
4. Which is a type mismatch (TypeError) in Python?
5. You want to print 'Total: ' followed by the integer total. Which works without a TypeError?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1'5' + 3 | AThe integer 16 is added to strings without conversion, causing a TypeError. It should be str(16) or the number should be written as '16'. | |
| 2int('5') + 3 | BRaises a TypeError because a string cannot be added to an integer | |
| 3input() always returns a string, so convert it with int() before doing maths | Cinput() returns a string, so multiplying it by a float causes a TypeError. It needs float(input('Qty: ')) or int(input('Qty: ')). | |
| 4To join a number to text, convert the number to a string with str() | DConverts the string to an integer first, so the answer is 8 | |
| 5total = input('Qty: ') * 2.5 | Eprint('Score: ' + str(10)) | |
| 6print('You are ' + 16 + ' years old') | Fage = int(input('Age: ')) + 1 |
C
Definitions
TypeError
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
total = ___(input("Enter a number: ")) + 5
2.
print("Score: " + ___(score))
3.
try:
total = '5' + 3
except _________:
4.
num = int(_____("Enter a number: "))
5.
age = input("Age: ")
print(____(age))
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
age = int(input("Age: "))
B
years = 5
C
total = age + str(years)
D
print(total)
Question 2
A
name = input("Name: ")
B
score = 7
C
msg = name + score
D
print(msg)
Question 3
A
num = input("Number: ")
B
result = num + 10
C
print(result)
Question 4
A
count = 3
B
label = "Items: " + count
C
print(label)
Question 5
A
a = input("First: ")
B
b = input("Second: ")
C
total = int(a) + b
D
print(total)
Answer Key
Runtime error: type mismatch
Section A: Quick Questions
Q1
A — TypeError: it cannot add a string and an integer
Q2
A — input() returns a string, so age + 1 mixes str and int
Q3
B — age = int(input('Age: '))
Q4
A — 'Score: ' + 10
Q5
B — print('Total: ' + str(total))
Section B: Match the Pairs
Q1
'5' + 3 → Raises a TypeError because a string cannot be added to an integer
Q2
int('5') + 3 → Converts the string to an integer first, so the answer is 8
Q3
input() always returns a string, so convert it with int() before doing maths → age = int(input('Age: ')) + 1
Q4
To join a number to text, convert the number to a string with str() → print('Score: ' + str(10))
Q5
total = input('Qty: ') * 2.5 → input() returns a string, so multiplying it by a float causes a TypeError. It needs float(input('Qty: ')) or int(input('Qty: ')).
Q6
print('You are ' + 16 + ' years old') → The integer 16 is added to strings without conversion, causing a TypeError. It should be str(16) or the number should be written as '16'.
Section C: Definitions
Q1
TypeError — A runtime error when an operation gets the wrong data types, like '5' + 3 (string plus integer). Fix it by converting with int() or str(), e.g. int(input()).Section D: Fill in the Blanks
Q1
total = int(input("Enter a number: ")) + 5Q2
print("Score: " + str(score))Q3
try:
total = '5' + 3
except TypeError:Q4
num = int(input("Enter a number: "))Q5
age = input("Age: ")
print(type(age))Section E: Spot the Error
Q1
C — age is an integer, but str(years) is a string. Adding an int to a str raises a TypeError. Both values must be numbers: total = age + years.
Q2
C — name is a string and score is an integer, so + causes a TypeError. Convert the number with str(): msg = name + str(score).
Q3
A — input() always returns a string, so num + 10 on the next line adds a string to an integer and raises a TypeError. Wrap it: int(input("Number: ")).
Q4
B — You cannot join a string and an integer with +. This causes a TypeError. Convert the integer first: "Items: " + str(count).
Q5
B — b is left as a string because input() was not converted. Then int(a) + b adds an integer to a string and raises a TypeError. Use int(input("Second: ")).