One technical question of Spreadsheet

For Spreadsheet, i am confused. Why is there usually with symbol"+" in front of the formulas?
Is it compulsory? If not, does it mean wrong answer?
I do not understand, can somebody explain it? I put one example below and circle the technical part.
Thank you very much.

Is it compulsory? If not, does it mean wrong answer?
I do not understand, can somebody explain it? I put one example below and circle the technical part.
Thank you very much.

0
Comments
If I write the number 10, we naturally assume that it's +10 and not -10 as that's the default we use the computer is just displaying it on the equations.
ACCA in progress
F4- Passed Aug 2020
F5- Planned for Dec 2020
F6- Passed Sep 2020
F7
F8
F9
For the + symbol. Do you mean that it is setted default in that excel for output the answer.
If i do not set it, then use the excel in the computer, so there is not + symbol output.
Oh, it will spare time, and i am glad to hear it.
For the + symbol. Do you mean that it is setted default in that excel for output the answer.
If i do not set it, then use the excel in the computer, so there is not + symbol output.
The number 10 on it's own is the same as writing +10 I'm not sure what setting would cause it to do that but that's all it is and you should not lose marks for having it appear in the exam.
ACCA in progress
F4- Passed Aug 2020
F5- Planned for Dec 2020
F6- Passed Sep 2020
F7
F8
F9
Thank you for your answer.