Free Addition Worksheets - Homeschool Math With the advanced options you can create missing number worksheets, addition problems with 3-6 addends, and additions without carrying (regrouping).. The option Switch addends randomly switches the order of the numbers to be added. For example, if you set addend 1 to be multiples of ten and addend 2 to be multiples of hundred, you will get such problems as 20 + 300 and 400 + 70.