always remember to: please excuse my dear aunt sally
TRANSCRIPT
ALWAYS follow this order:• Parentheses• Exponent •Multiply or Divide (from left
to right)• Add or Subtract (from left to
right)
KEY CONCEPTS1. Do every expression within the
parentheses (in order).2. Find the value of all powers.3. Multiply or divide in order from
left to right.4. Add or subtract in order from
left to right.
Now, let’s look at a problem two different ways…This will prove why
order IS important.
5 + 3 x 28 x 2 = 16
This is NOT correct. The correct order of
operations has not been followed. Let’s
do this problem correct!
Sung to the tune of “Deck the Halls”
Please excuse my dear Aunt SallyThis is the order of operationsParenthesesThen the exponentThis is the order that it goes…Multiply or DivideDo this in order from left to rightThen you add or subtractDo this also from left to right.Please excuse my dear Aunt SallyThis is the order in which it goes.
Let’s practice.
Note to teacher: You can work the following problems on the board, Elmo, whiteboards, etc. Students can even work it out on the TV screen with a dry erase marker)
(11-7) x 3 - 5
Answer: 7
Here’s a challenge!
96 ÷ 4² + (25 x 2) - 15 - 3 Hints:• Solve the
parentheses• Don’t forget the
exponent• Next divide• Then add• If you have two of
the same operation (subtraction) do those from left to right
Answer: 38