Given a number return the closest number to it that is divisible by 10.
Example input:
```
22
25
37
```
Expected output:
```
20
30
40
```
def closest_multiple_10(i):
    r = i % 10
    return i - r if r < 5 else i - r + 10
def closest_multiple_10(i):
    r = i % 10
    return i - r if r < 5 else i - r + 10