Mot du Jour

 

Order of Operation & Scientific Notation Review

Mikhail bought 2 burgers for $3.50 each and 3 medium French fries for $1.20 each. Write a numerical expression to represent this situation and then find the cost. 

Mackenzie pays 20 dollars for materials to make earrings. She makes 10 earrings and sells 7 for 5 dollars and 3 for 2 dollars. Write a numerical expression to represent this situation and then find Mackenzie's profit?

The price of a shirt is 100 dollars. The store manager gives a discount of 50 dollars. A man and his brother bought 4 shirts and then share the cost with his brother. Write a numerical expression to represent this situation and then find the price paid by each brother.

Mr. Dixon withdrew 1000 dollars from his bank account today. He uses 500 to fix his car. Then, he divide the money into 5 equal parts and gave away 4 parts and kept 1 part for himself. Finally, he took to wife to the restaurant and spent 60 dollars on meals. Write a numerical expression to represent this situation and then find how much money Mr. Dixon has now?

(Note: Pluto is no longer considered a planet)

Which is the ‘lightest’ planet? How do you know? 

Earth is ‘heavier’ than Venus? True or False? How do you know? 

Which is the ‘heaviest’ planet? How do you know? 

In standard form, does Pluto have 22 zeroes after the 9? Why or why not? 

Pick a planet and write it out in standard form. 

Order the planets (don't include Pluto) from "lightest" to "heaviest".

Order of Operations

Margot volunteers at a local bird sanctuary. She just spent two weeks on vacation, so on her first day back she is talking to her supervisor about what she has missed. When Margot left, there were 256 birds. In her absence, 3 birds have each given birth to 5 baby birds, 2 birds were released into the wild and 3 new injured birds were brought in. How can Margot write an expression to figure out the new sanctuary population?

An equation is a number sentence that describes two values that are equal to each other. The values are separated by the "equals" sign, e.g. 3 + 4 = 7. In this case, 3 + 4 and 7 are equal entities. Sometimes you will be given an incomplete equation, which you have to "solve" in order to make both sides equal.

An expression is a number sentence without an equals sign. It can be simplified and/or evaluated, but it cannot be "solved".

Expressions can involve more than one operation, so it is important to know which operation to do first. The order of operations tells you the correct order for completing operations within an expression.

Order of Operations
P - parentheses
E - exponents
MD - multiplication or division, in order from left to right

AS - addition or subtraction, in order from left to right

Now, let's return to Margot and her bountiful birds.

Margot needs to write and evaluate an expression to see how the original population of 256 has changed since 3 birds each gave birth to 5 baby birds, 2 birds were released, and 3 injured birds were brought in.

First, identify the important information in the problem.

256 birds to start

3 birds have 5 babies each

2 birds released

3 birds added

Next, write this as an expression.

256+3×5−2+3

Then, use order of operations to evaluate the expression.

256+3×5−2+3256+15−2+3271−2+3269+3272Multiply 3×5Add 256+15Subtract 271−2Add 269+3===-

The answer is 272.

Margot’s sanctuary now has 272 birds

YOUR TURN: 

Evaluate the following using order of operations

1. 2+3×4+7=––––– 
2. 4+5×2+9−1=––––– 
3. 6×7+2×3=––––– 
4. 4×5+3×1−9=––––– 
5. 5×3×2+5−1=––––– 
6. 4+7×3+8×2=––––– 
7. 9−3×1+4−7=––––– 
8. 10+3×4+2−8=––––– 
9. 11×3+2×4−3=––––– 
10. 6+7×8−9×2 
11. 3+42−5×2+9=––––– 
12. 22+5×2+62−11=––––– 
13. 32×2+4−9=––––– 
14. 6+3×22+7−1=–––––

Original lesson