Please can someone it well for me, i can't understand it very well

Question

# PROBLEM - ADD ROUND
"""
Write two functions. The first should round an integer up to the next multiple of 10 if
the rightmost digit is 5 or greater, else round it down to the previous multiple of 10.
The second function should return the sum of the rounded values of two integers.

Sample Output:
_____________________________________
Input: Output: |
_____________________________________|
add_round(7, 4) | 10 |
add_round(7, 8) | 20 |
add_round(14, 16) | 30 |
add_round(15, 15) | 40 |
___________________|_________________|

"""

def add_round(a, b):
return round(a) + round(b)

def round(num):
return num - (num % 10) + 10 if num % 10 >= 5 else num - (num % 10)
print(add_round(14, 16))

Answer 1

The trick is in the return statement of def round.

If you write it differently it would be:

#round up
if num % 10 >= 5:
return num - (num % 10) + 10
#round down
else:
return num - (num % 10)

For example 14 % 10 will be 4, so it will do the else branch: 14 - 4 = 10
16 will do the if branch, because 16 % 10 = 6 so: 16 - 6 + 10 = 20

Answer 2

return num - (num % 10) + 10 if num % 10 >= 5 else num - (num % 10)
Can be thought as:
if num % 10 >= 5:
return num - (num % 10) + 10
else:
return num - (num % 10)
(num % 10) returns the ones digit so 4 of 14 or 7 of 7.
num - (num % 10) rounds down.
num - (num % 10) + 10 rounds up.

Answer 3

def round(num) basically says
return this if condition is true else return this