## Introduction: Having Fun With a Calculator and a Friend (meant for School, But Works Everywhere)

This is my first instructable, so DON'T be too forgiving, it's better to learn from criticism than not learning at all.

Continuing, the past year I found myself in a different desk from the one I was in the year before, and with a different deskmate. While with the old one we could easily chat for hours (about music given that we play together in a little band), with the newer one we had nothing to talk about, and the day passed so slowly that I came back home way too tired considering that all I did was staying 5 hours on a chair doing nothing. BUT, in the second half of the year I had an idea with a thing I discovered: the calculator.

Yes, that was what kept us entertained the second quadrimester. I thought of something, mainly using the Random function of the calculator (it's on pretty much all of the scientific calculators, on some it works better and on some it's a little more difficult, but it's there).

The calculator you can see on the top of this post is the one I've got, though I just broke my camera (to be honest, my brother did), and then I've got to look for images over the net.

Let's start:

## Step 1: Familiarize With Your Calculator

Hopefully, you know how your calculator works, for most things, but there are some buttons that many of you don't use and thus don't know. The one we're going to "study" is the random button. As you can see from the image, my button is the second button of the lowest row, but I'll need to press shift, too. On your calculator there could be a "random" button, or a "Ran" or, like me, "Ran#", and it could need other buttons to be pressed to enable it, like shift. There are different kinds of randomizers on the calculators. For example, my deskmate from this year had a calculator that had a "random" button, and when you pushed it a menu with "1 Dice, 2 Coin, 3 Define" appeared, meaning that if you wanted to simulate a Dice you had to press 1. for a Coin you had to press 2, and for a manual one, you'd have to press 3.

If you happen to get one like that, you're lucky, because it is exactly what we need for this. If you got one like mine, a lot simplier but less specific, you'll just need to understand how it works.

In my case, to randomize a dice you'd have to push "6" and then "shift"+".". What it does, though, is randomizing a number from 0 to 6, without 0 and 6 themselves and with 4 decimal digits. What we did is "let's consider all the number with a 0 as the entire digit as 1, the ones with 1 as 2 and so on". Doing so, 1 (as a dice number) had a slightly inferior probability to get extracted, but it was so little that it didn't matter.

Play around with your calculator, then come back to read this instructable after you fully understand how your randomizer works.

## Step 2: Tetris

**Setup:**

This is the first game I invented. I set the randomizer to 7, so that it randomized from 0 to 7, then I drew the playfield. To be precise, I made it 10x18, but I don't know about the original one's exact sizes.**Playing:**

Once you drew what's needed and setupped your calculator to the right randomizer so that it extracts randomly between 7 objects, you have to choose who starts playing. You can do so randomizing once each and see who's got the bigger number.

Now the one who doesn't play randomizes, the object that he randomizes is the one you should try to fit in. It follows the usual rules of the good ol' tetris, but without a time limit. You can set that too if you have got a timer or something, but generally a countdown from the non-playing one works. This is the one we liked the most this year, expecially if one of you starts singing Tetris' theme.

## Step 3: Game of the Goose

Assuming you don't have enough time for Monopoly, even though you could elaborate a simpler version of it, here we go with one of the most classical games.**Setup:**

Draw your map, you can use all of your imagination here, we (me, my deskmate and other two friends) realized about 6 or 7 maps, with cars, running peoples, spaceships and whatever you can think about. You can even make up your rules. For example, in the car one, we had a place where if you went too fast (means that if you had 6 or more spare movements from your dice toss) you "jumped" the cliff and went on the other side and continued moving, and an almost identical one where, if you went too fast (same rules as before) you fell and died (had to start back from the starting point). After you made clear your rules, set your calculator. If you have one with the random dice, you can use that function, then press "+" and use that function again so that it automatically sums your tosses. If you have one like mine you have to randomize like before for a dice, see what you tossed and then toss again, after that, you sum your tosses up. You have to do this because if it randomizes 0,984 and 1,012, you'd obtain 1,996, which means 2, while the real result would be 3, because 0=1, 1=2, 1+2=3.

As moving pieces you can use a piece of paper and write on it to identify which one is yours and which one is your opponent's.**Playing:**

Decide who's going first with the usual dice toss, then start playing. Follow the rules and have fun. If you follow the rule "when you exceed the number needed to get to the end you go back", when you're near the end, use only a dice, instead of two.

## Step 4: Reviewed Tic-Tac-Toe and Connect 4

While you can easily play each one of those without the help of a calculator, doing with one makes the game more luck-reliant and funny.**Setup:**

Prepare your calculator so that it generates a number between 0 and 2, or, if you have it, a coin toss. If you're using the former, always round down the result. Decide which game you're going to play, and draw a table accordingly. For Connect 4 it is a 9-width and-6 height table, for Tic-Tac-Toe, a 3x3.**Playing:**

After you chose the game, decide if you'd rather be 0 (O) or 1 (X) with your opponent. Then get into the game. The gameplay is similar for both, so you'll just have to adapt this rule to the regular rules of the game.

It's A turn, A, that has 1, chooses an open space. He then tosses the coin. If it is 0, A writes O in there, if it is 1, A writes X instead. It then shifts to B and then back to A and so on till one of them wins.

If you're wondering why we applied this rule even though the games were perfectly doable by themselves, it's easy to answer. Tic-Tac-Toe will always be, if both player know how to play, a draw. With this rule we found it a lot funnier, and decided to apply it to Connect 4, too.

## Step 5: Chinchirorin/Cee-lo

**Setup:**

Calculator with one dice and possibly somewhere where you can write your points. Still, with two players you may want to modify the rules. Read this, it has all of the necessary rules.**Playing:**

You may want to abolish the Banker role and just play one against the other one if you are only two. In that case, you may want to extablish other rules. Some suggestions:

-There's a "turn player", basically, it has the advantages and duties of the Banker, but restricted. Being the banker, you'll have to follow the other's bets, but if you have the same points of the other player, you win.

-There are no auto-win/auto-losses.

-The order of the points should be:

.123

.xx1

.xx2

.xx3

.xx4

.xx5

.xx6 (the opponent pays double the bet if he loses)

.222

.333

.444

.555

.666 (the opponent pays double the bet if he loses)

.456 (the opponent pays triple the bet if he loses)

.111 (the opponent pays five times the bet if he loses)

## Step 6: Creating Your Own Game or Adapting an Existing One

Needless to say, I may go on and on with this for hours, but once you're given the ability to flip a coin or toss a dice, you should know that you can afford lots of games. You can create your own or you can adapt an existing one (like we did with tetris). Pretty much everything with randomization (but in which both of the players can see what has been randomized) is affordable, giving us an even better range of games. Try for yourself and post under the comments your results, I look forward to see tham.

Cool, how did you draw a grid for the Tetris game?

If you mean when we want to play, well, the diary usually is more than enough. If you mean how I drew it for the instructable, well, I had GIMP already opened, I just drew it with a grid on.