Request a numeric input, and then multiply the input by 10.

prompt = 'What is the original value? ';
x = input(prompt)
y = x*10

At the prompt, enter a numeric value or array, such as 42.

x =
    42

y =
   420

The input function also accepts expressions. For example, rerun the code.

prompt = 'What is the original value? ';
x = input(prompt)
y = x*10

At the prompt, enter magic(3).

x =
     8     1     6
     3     5     7
     4     9     2

y =
    80    10    60
    30    50    70
    40    90    20

prompt = 'Do you want more? Y/N [Y]: ';
str = input(prompt,'s');
if isempty(str)
    str = 'Y';
end

The input function returns the text exactly as typed. If the input is empty, this code assigns a default value, 'Y', to str.