Math module introduction example in lesson 04-functions results in an error about py4e HOT 3 CLOSED

This is something common in the book,
e.g. 2.11 percentage=(minute100)/60 #minute is not defined
2.13 interest = principle rate, etc
These are examples that show something specific and cannot be treated as a whole program

from py4e.

Hi Krishnakumar,
This example is given as an illustration of how math module can be applied in terms of ratios hence no specific values have been declared. Hope it helps.

from py4e.

Yes. I understand that. However, it is noteworthy that out of all code blocks presented all the way from the very first chapter until now, only this one errors out (because the variables have not been defined).

This is likely to cause confusion to beginners (whom the course targets). It would be better to update the lesson wherein the variables are defined in the codeblock just prior to the SNR division statement, thereby providing a frictionless experience for those trying it out on their interactive python REPLs.

from py4e.