The inequality x > 3 means all numbers greater than 3. The set of numbers that makes the inequality true is called the solution set of the inequality. An instance of this numbers such as 4 is a solution to x > 3.
The graph of x > 3 is shown on the number line below. The “empty circle” means that the solution does not include 3. The highlighted part of the number line (blue ray) means that it includes all real numbers greater than 3 and the arrow indicates that it goes up to infinity.
Another notation to represent x > 3 is (3, ∞). The number on the left side is the lower bound and the right side is the upper bound. This notation means from 3 up to infinity. In addition, the symbol ( denotes that 3 is not included in the solution. Therefore, the interval (5,7) means all real numbers from 5 to 7, not including 5 and 7. The infinity symbol always takes the ( and ) symbols. Continue reading
Perhaps the saddest news this week are the deaths of famous mathematician John Nash, 86, and wife Alicia, 82 in a car accident last Saturday, May 23. Nash was known for his work in Economics (Game Theory) particularly on the Nash equilibrium as well as his contributions real algebraic geometry. He received the Nobel Prize for Economics in 1994, a Double Helix Medal in 2010, and an Abel Prize this year.
image via Wikipedia
The life of John Nash, particularly his battle with paranoid schizophrenia, was detailed in Sylvia Nasar’s A Beautiful Mind which was later made into a Hollywood film where Nash was portrayed by Russell Crowe.
Many people expressed their grief on Nash’s death through Twitter and other social media sites. His death is truly a big loss to the mathematics community.
If you want your children or students practice equations and operations, you might want to try Equate: The Equation Thinking Game. Equate is a math board game that works like Scrabble. In Equate, instead of forming words, you can form equations. Younger children can choose an easy game which only consists of addition and subtraction, while older children can include multiplication and subtraction. Even more challenging is to include fractions!
Just like Scrabble, you can have double or triple scores in Equate. This can make players think of equations that yields a larger answers, while practicing their arithmetic.
Equate can be played 2-4 players ages 8 years old and above.
Although this game is challenging, it could also take a while to finish one game. Games which include fraction is expected to last up to 120 minutes.