Common mistakes in math 

Find here a list of common mistakes in math made by students on a regular basis. Check the list and avoid making them yourself.

Mistake #1:


Incorrect: 4³ = 4 × 3

Correct: 4³ = 4 × 4 × 4


Mistake #2:


Incorrect: -3² = -3 × -3 = 9

Correct: -(3 × 3) = -9


Mistake #3:







Mistake #4:


Incorrect: -5 + 15 = -20

Correct: -5 + 15 = 10

Mistake #5:

Incorrect: √(9 + 16) = √9 + √16 = 3 + 4 = 7

Correct: √(9 + 16) = √(25) = 5

Mistake #6:


Incorrect:
x + 8 > 10
x + 8 - 8 < 10 - 8
x = 2

Correct:
x + 8 > 10
x + 8 - 8 > 10 - 8
x > 2


Mistake #7:


Incorrect: y³ × y² = y⁶

Correct: y³ × y² = y⁵


Mistake #8:


Incorrect: (2y)⁴ = 2y⁴

Correct: (2y)⁴ = 16y⁴


Mistake #9:


Incorrect: 4 × (2z + 5) = 4 × 2z + 5

Correct: 4 × (2z + 5) = 4 × 2z + 4 × 5


Mistake #10:


Incorrect:
x + 10 = 20
x + 10 - 10 = 20 - 10
0 = 10

Correct:
x + 10 = 20
x + 10 - 10 = 20 - 10
x + 0 = 10