how to round up numbers please?

Excel has a Max and a Min function these return the highest and lowest numbers in a list. The Integer function will remove all remainders from a result. Round can be mset to any place 1's 10's
100's, 1,000's...

Data validation can be set, Data-Validation, to only allow values between indicated Min and Max values else and Error box Msg.

Your question is ambiguous to me?
Hope the above has helped you? JSW

This is the sheet function to round up to thousands & hundreds!

=ROUND(Cell Reference,-2)
Like: =ROUND(A1,-2) in B1.
For A1 = 123,456 B1 will give 123,000.
=ROUND(A1,-1) = 123,400

If this is what you want? JSW