Spaces are not needed to separate operands and operators in arithmetic expressions. Extra spaces are OK (but don't put spaces inside numbers or identifiers.) Unneeded parentheses are OK. Sometimes they make things clear to a human reader. All of the following evaluate to the same value:
| 45 + 15 | 15+45 | (45+15) |
| (45) + (15) | ((45)+(15)) | ((45+15)) |
| 15 +(45) | 15+ 45 | ((45)+15) |
The expressions in the last two lines have correct syntax, but are unclear, and should be avoided.