[Rescued from my old blog.]
Paraphrased from a homeschool math discussion forum:
“I am really struggling with percents right now, and feel I am in way over my head!”
Percents are one of the math monsters, the toughest topics of elementary and junior high school arithmetic. Here are a few tips to help you understand and teach percents.
Are your students ready for a challenge?
The Math Forum: 2007 Mathematics Game will be a tricky one:
Use the digits in the year 2007 and the operations +, -, x, ÷, sqrt (square root), ^ (raise to a power), and ! (factorial), along with grouping symbols, to write expressions for the counting numbers 1 through 100.
- All four digits must be used in the expression.
- Only the digits 2, 0, 0, 7 may be used.
- Multi-digit numbers such as 20, 207, or .02 MAY be used this year.
- The square function may NOT be used.
- The integer function may NOT be used.
[Rescued from my old blog.]
Marjorie in AZ asked a terrific question on the (now defunct) AHFH Math forum:
“…I have always been taught that the order of operations (Parenthesis, Exponents, Multiplication, Division, Addition, Subtraction) means that you work a problem in that order. All parenthesis first, then all exponents, then all multiplication from left to right, then all division from left to right, etc. …”
Many people are confused with order of operations, and it is often poorly taught. I’m afraid that Marjorie has fallen victim to a poor teacher — or at least, to a teacher who didn’t fully understand math. Rather than thinking of a strict “PEMDAS” progression, think of a series of stair steps, with the inverse operations being on the same level.
[Rescued from my old blog.]
Division of fractions is surely one of the most difficult topic in elementary arithmetic. Very few students (or teachers) actually understand how and why it works. Most of us get by with memorized rules, such as:
Ours is not to reason why;
just invert and multiply!
Denise Gaskins' Let's Play Math 