First of all, congratulations to the following students in our class who have won in the recent school wide Math contest:
Karen Li is the sole 1st place winner in the 6th grade category with $20 prize.
Eugene Jiang, Robert Sheng, Alexander Deng, Jiming Xu are among other prize winners in the 6th grade category and will each get $10 prize.
Congratulations again!
Since we have finished covering the regular content in the textbook, I am adding a little more today. For the last two lessons, we will have review and final exam.
We study combinations and permutations, with the introduction of factorial. A combination is a group of outcomes where the order does not matter, while permutation is a group of outcomes where the order does matter. Factorial is a way of computation. The factorial of a number is the product of the number and all the natural numbers less than the number.
n! = n x (n-1) x (n-3) x … x 3 x 2 x 1
The number of permutations of choosing r things out of n things at a time is denoted as nPr and
nPr = n! / (n-r)!
The number of combinations of choosing r things out of n things at a time is denoted as nCr and
nCr = n! / [r! x (n-r)!]
Today’s material can be found here for Section 10.8.
Homework: download this page
Page 765, #12 – #23.