#1 - Easy Math Rebus Puzzle
what does the below math rebus puzzle means ?

ground floor
A maths symbol is hidden in the below rebus. Can you decipher it?
Pie
This is the bar graph that represents the number (3, 1, 4, 1, 5, 9, 2, 6, 5) .
and we know the value of pie is 3.14159265
What does the below rebus maths means ?
Quadratic, quad(4 wheeler + rat + i (eye) + C)