57- 1 1 equals 46,57-11= 46. In subtraction calculation, if the mantissa of the minuend and the minuend is the same, subtracting the minuend with the same mantissa first can make the calculation simple. The subtraction algorithm includes subtraction combination, subtraction algorithm and subtraction exchange rule. Subtraction is one of the four operations, and the operation of subtracting one number from another is called subtraction. Knowing the sum of two addends and one of them, we can find the other number.