[MP2]

Not entirely sure what you mean. From what I understand you want to get the value of what was entered and add 45 per 1000?

value = strval(inputtext);
value = value + (45*(value / 1000))

Tested it, works fine.

If you want to add it for every value (i.e. 500 will add 22.5 (half of 45)) then:

new value = strval(inputtext);
value = floatround(value + (0.045*(value)));