Decimal Rules
Adding and Subtracting:
When adding and subtracting decimals, you line up the decimals. This forces you to
add and subtract like place values (tens are added to tens, ones to ones, etc.)
Mulitplying:
When multiplying decimals, disregard the decimal and multiply. Then count the
number of spaces the decimal is over from the right in each factor, sum the total of
the two, and put that many decimal spaces in your product.
Dividing:
Simply say “no” and only divide using whole numbers. Do this by moving the
decimal in the divisor over to the right until it is a whole number. Then move the
decimal in the dividend over the same number of spaces, adding zeroes if necessary.
Then move the decimal up in the quotient. (over, over, up rule)