Sometimes the numbers a program generates need to be changed so they work within a given range. Sound volume in Scratch for examples works between values of 0 and 100. There's no point therefore in using a volume of 200, since the maximum accepted value is 100. To solve this issue, it may be necessary to use numerical operators to alter the value of variables to make them more usable. In this program you will learn how. You will then use this skill to debug a burglar alarm program in which a variable is not working within a correct range of values.