YOU SAID:

i don't understand a thing from maths classes

INTO JAPANESE

私は数学のクラスから物事を理解していない

BACK INTO ENGLISH

I don't understand things from math class

INTO JAPANESE

私は数学の授業から物事を理解していない

BACK INTO ENGLISH

I don't understand things from math classes.

INTO JAPANESE

私は数学の授業から物事を理解していません。

BACK INTO ENGLISH

I don't understand things from math classes.