What does the little arrow with no shaft pointing upwards mean in maths?

this arrow ^ means "to the power of"

E.g.

4^2 means 4 to the power of 2

the power is how many times it is times by itself.

4^2 is, two 4's multiplied together = 4 x 4 =16

4^3 is, three 3's multiplied together = 4 x 4 x 4 = 64