I had the MS Calculator set to standard not scientific, when I changed to scientific I got the correct percentage number.
How come you multiple the number again;
2345 - .45 x /2345/ ?
You have the number and you want to reduce it by 45%. First you calculate what 45% of the number is and then you would subtract it from the number.
If it ain't broke, fix it until it is.
A number by itself is useful, but it is far more useful to know how accurate or certain that number is.