1-29In each example, you cannot subtract 1 from 0 and have a positive difference. You must use aborrow from the next column of numbers. Let’s examine the above problems and show the borrow as adecimalquantity for clarity:When you use the borrow, the column you borrow from is reduced by 1, and the amount of theborrow is added to the column of the minuend being subtracted. The following examples show thisprocedure:In the octal example 7_{8} cannot be subtracted from 6_{8}, so you must borrow from the 4. Reduce the 4by 1 and add 10_{8} (the borrow) to the 6_{8} in the minuend. By subtracting 7_{8} from 16_{8}, you get a difference of7_{8}. Write this number in the difference line and bring down the 3. You may need to refer to table 1-4, theoctal addition table, until you are familiar with octal numbers. To use the table for subtraction, followthese directions. Locate the subtrahend in column Y. Now find where this line intersects with the minuendin area Z. The remainder, or difference, will be in row X directly above this point.Do the following problems to practice your octal subtraction:Q30.Subtract:Q31.Subtract: