# Tag Archives: order of operations

## To Your Station Mister, We’re Evaluating Expressions

Have you ever had one of those teaching days when you’re like, “Wow! This is really working!”? Well, I did today. For years, I have always wanted to set up stations in my classroom to allow students to move around the room, work in groups, and do different things throughout the hour. I was lucky enough to find a book on eNasco.com that is built around “stations” for math. Because of my class sizes, I set up two sets of four stations, a set of “A” stations and a set of “B” stations. The stations were four groups of desks, a manilla file folder with the station number, and whatever materials were needed for that station. The following is a list of the stations and their required materials:

Station 1: Worksheet, one dice, a set of 5 index cards with the following expressions written on them:
3n + 4,  2m^2,  15 – x,  60 / p,  2x – 2

Station 2: Worksheet

Station 3: Worksheet

Station 4: Worksheet, set of 5 index cards with the following expressions written on them:
2x + 2, 5 + x, 36 / x,  16 – x,  2x^2

set of 5 index cards with the following values of x written on them:
x = 2, x = 3, x = 4, x = 5, x = 7

Give the students ten minutes at each station. The worksheets explain how to conduct each station, but I still had to help a few of the groups. The following pictures are of the worksheets for each station.

## Please Excuse My Dear Aunt Sally……

If you are a math person, you’ve probably heard about dear Aunt Sally. It is a mnemonic that helps students remember the order of operations (the order in which we work a series of numbers and operations). It is “Please Excuse My Dear Aunt Sally. Please is for parenthesis, Excuse for exponents, My for multiply, Dear for divide, Aunt for addition, and Sally for subtraction. Every math teacher I know uses it and if they don’t, then they probably should.  I taught the students the mnemonic, worked several examples, had them work several examples, gave them a short worksheet, and then today we played a game. The game was a set of 40 pieces of paper cut up into about 2″ by 4″ or 5″. I wrote a different numeric expression on each paper. The students were in groups of three or four. Each group got a set of the cards and a dice. The whole set of cards was placed upside down in the middle of the group. The first person rolled the dice and flipped over a card. They worked the problem on the card while (at least) a second person worked the problem as well, as a “checker”. If the person got it correct, they added the number on the dice. If they got it incorrect, they deducted the number of points on the dice. It was absolutely hilarious to listen to the students argue and correct each other the whole time they played. There was very little off-task conversations. They occassionally asked for my help, but not often. It was a very successful game and lesson! It sometimes got very loud in the room, but what was I going to say, “Quit talking so loud about math!”? Uuummm… NO! I’m goint to post pictures of the cards I made up, but honestly I just got them out of the book.

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