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.