Wednesday, June 17, 2009
My Special Number: 25
For many years I assigned an end-of-unit project to my sixth graders titled My Special Number. This was when students would pick a number on which to perform a number study. Today I offer my own version of this assignment.
My special number is 25. It is a number that is described as odd, composite, and square. It is odd because it is not divisible by two. It is composite because its factor pairs are not only 1 x 25, but also 5 x 5. Having 5 x 5 as a factor pair is also what makes it a square number. In fact it is the smallest square number that is the sum of two other square numbers. ( 9 + 16 = 25) This relationship is found in many right triangles (known as 3-4-5 triangles) used for illustrating the Pythagorean Theorem.
Because 25 is a factor of 100, it is used in a variety of ways. A twenty-five cent coin is a quarter and it takes four to equal a dollar. 25% is equivalent to ¼.
The number 25 has significance in various religions and philosophies. According to Abellio, twenty-five is the symbol for the Universal Word of God. St. Augustin used it to represent the law. In the Bible, King Solomon builds a temple to God that is 25 cubits high, and a Levite could begin practicing his ministry at the age of twenty-five.
But today, the number twenty-five has a special significance. Today marks the day that indicates that FOR TWENTY-FIVE WONDERFUL YEARS I HAVE BEEN MARRIED TO THE BEST HUSBAND I COULD POSSIBLY HAVE!