COMPOUND ADDITION.

COMPOUND ADDITION is the adding together of two or more numbers of different denominations.

RULE.

Write all the given numbers of the same denomination under each other; then add the numbers of the first denomination together, and divide the sum by so many as make one of the next denomination; set the remainder under its column, and add the quotient to the next column; which add together and divide as before; thus proceed to the last denomination, under which, place its whole sum.

COMPOUND SUBTRACTION.

COMPOUND SUBTRACTION teaches to find the difference between numbers of different denominations.

RULE.*

Write those numbers under each other, which are of the same denomination, the less compound number under the greater; begin with the lowest denomination, and, if it exceeds the number over it, add as many units to the upper number, as it takes of that denomination to make the next higher; then subtract and carry one to the next number of the subtrahend.

* The reason of this rule will readily appear, from what was said in Simple Subtraction; for the adding to the upper line depends on the same principle, and is only different, as the numbers to be subtracted are of different denomi nations.