Posted by David Wetzel
Order of Operations
When there is more than one operation involved in a mathematical problem, it must be solved by using the correct order of operations.
When using a calculator, it will perform operations in the order which you enter them. Therefore, you will need to enter the operations in the correct order for the calculator to give you the right answer.
Order of Operations Acronyms
Use the following Acronyms to help remember order of operations:
Please Excuse My Dear Aunt Sallie (Parenthesis, Exponents, Multiply, Divide, Add, Subtract)
or
Pink Elephants Destroy Mice And Snails (Parenthesis, Exponents, Divide, Multiply, Add, Subtract)
Order of Operations Rules
1. Calculations must be done from left to right.
2. Calculations in parenthesis are done first. When there are more than one set of parenthesis, do the inner parenthesis first.
3. Exponents must be done next.
4. Multiply and divide in the order the operations occur.
5. Add and subtract in the order the operations occur.
Order of Operations Examples
12 ÷ 4 + 32
12 ÷ 4 + 9
3 + 9
12
Rule 3: Exponent first
Rule 4: Multiply or Divide as they appear
Rule 5: Add or Subtract as they appear
20 ÷ (12 - 2) X 32 - 2
20 ÷ 10 X 32 - 2
20 ÷ 10 X 9 - 2
18 - 2
16
Rule 2: Everything in parenthesis first
Rule 3: Exponents
Rule 4: Multiply and Divide as they appear
Rule 5: Add or Subtract as they appear
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Filed Under: Math
Posted by David Wetzel
Solar Water Distiller
Students use hands-on inquiry based science to investigate the water distillation process using solar energy.
The purpose of this experiment is to determine if pure water can be distilled from dirty water.
Materials: (Per Group of Students)
1 Large Clear Plastic Container
1 Small Glass
1 Small Rock
1 Tablespoon
2 Tablespoons of Dirt
Clean Water
Duct Tape
Clear Plastic Wrap
Hands-On Procedures:
1. Tape the empty glass to the bottom of the large clear bowl, open side up.
2. Add water to a point below the glass opening, ensure clean water does not enter glass.
3. Add 2 tablespoons of dirt to water and stir.
4. Cover opening of bowl with plastic wrap and place small rock in center.
5. Place completed bowl setup in sunny location or use a heat lamp if sunny location is not available.
Inquiry Based Hypothesis Development and Discussion:
1. Students predict if the outcome of the experiment during construction of their Solar Water Distiller.
2. Students make observations of their Solar Water Distiller for 5 days.
3. Students discuss the outcome: Was their hypothesis supported? What evidence do they have to support their findings? What would happen if salt was used instead of dirt? What about sugar?
Posted by David Wetzel
Interactive Math
Vector Kids provides opportunities for elementary and middle school math students to strengthen their basic math skills using interactive math games and tools.
Interactive Math Activities and Games
The following are examples of interactive math content areas included in Vector Kids:
Divisibility Rules: students learn divisibility rules through an interactive game.
Time Flash Cards: students try to solve as many math flash card problems as they can within one minute.
Flash Cards + & -: students solve math problems using addition and subtraction.
Flash Cards x & /: students solve math problems using multiplication and division.
Fractions: students solve fraction problems using pie charts.
Variable Solving: students practice basic algebra skills.
