# Wheel of Math

524

## Introduction: Wheel of Math

How to play:

A player has to predict 3 numbers before spinning the wheel. Press the switch so that the wheel spins, and when the wheel stops calculate the problem. If the answer is one of the number that a player has predicted, the player wins the game

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## Step 1: Prepare Materials

Gear 1: Number of teeth (N): 160 Pitch diameter (D): 40cm Diametral pitch (P): 4 Pressure angle (PA): 30

Gear 2: Number of teeth (N): 68 Pitch diameter (D): 17cm Diametral pitch (P): 4 Pressure angle (PA): 30

1. Styrofoam
2. 2 motors
3. Glue gun
4. 6 alligator wires
5. Copper wire
6. Cardboard
7. Paper
8. Pen
9. 4 Straws
10. 9 Volt battery
11. Utility knife

I made the gear using computer program and using laser cutter.

## Step 2:

I traced the outline of the 2 gears on the separate piece of paper. After tracing the outline, I divided it into 8 parts. In each part, I put different types of numbers. On the other gear, I put numbers with different signs such as +,-,*,^. Then I cut the gears out and pasted in to the gear.

## Step 3:

After I finished making gear, my next step was to build a frame that would hold the gears with motors. I used the Styrofoam to make the frame. With the utility knife, I measured the styrofoam and started cutting. I placed one big Styrofoam at the bottom. I placed another Styrofoam on top of the Styrofoam. It was placed with it about 45 degrees. Since the Styrofoam can not maintain the weight of the gear just by itself without anything, I added small piece of styrofoam in between to strengthen it. There was a problem to the styrofoam I was using. It wasn't straight, instead it was curved so I could not glue it easily. The amount of surface that would connect the 2 styrofoam was just the edge of it. I glued the edges with glue and used sticks and straws to connect. I realized that the small piece that I put between 2 big styrofoam wasn't also stable so I cutted smaller styrofoam to maintain that piece.

## Step 4:

I poked the styrofoam with any pointy object to make a hole. The hole is for the motor. I plugged in the gear to the motor with a styrofoam in between. I connected the motor with a 9 volt battery so that the motor spins. I tested it out, but it did not work out. There were 2 main problem. The problems were about friction and the that the gear wouldn't be fully attached to the motor. I tried about 20 different types of idea to solve the problems but none of my idea worked. At the last moment, my teacher gave me an advice to use the metal ring and surprisingly it worked! I put the metal ring before the gear so that the gear has less surface attached to the frame which lowers the frame. I used the straws to tighten the hole with gear and the motor. Using the straw was a success. My final step, to make a switch that can on/off the motor. I used a small cardboard that can be folded half. On the top of the cardboard I used one long copper tape and on the bottom I used 2 separate copper tape so that when someone pushes the switch, it would complete the circuit. Lastly connect the alligator wires to the copper tape and battery.

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