Always Have Correct Change in Your Wallet




Some people carry change purse with them where ever they go, but you won t use most of those coins. Why carry coins that you won t use? So what is the fewest number of coins you can carry that allows you to produce any exact change? And then find an inexpensive way to carry that in your wallet.

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Step 1: Theory

So what is the fewest number of coins you can carry that allows you to produce any exact change?The answer is 10 coins, 3 Quarters, 1 dime, 2 nickel, and 4 pennies. With this combination you can produce any number between 1-99 cents.

An alternative answer would be 6 coins, 3 Quarters, 2 dimes and 1 nickel. In this example you will range most change between 5-95 cents, in 5 cents increments. In this example you will never receive more than 4 cents in change back.

The project is a way to carry these 10 coins easily inside your wallet. I have used a thin piece of cardboard. But if you may use most anything, I recommend any material about 2 stacked coins thick, and have enough friction to hold the coins in place.

Step 2: Materials:

a Credit Card to draw template
A pen
3 Quarters
1 dime
2 nickels
4 pennies
sharp knife
Thin Cardboard
30 minuets to an hour of free time

Step 3: Draw and Cut

First get the cardboard, use a credit card and your pen to draw a template.

Step 4: Draw Your Coins

Place coins on template. Use pen to trace your coins. Put them generally where I have them place. Now when your tracing remember the cardboard must support itself when you cut the coins out. So don t have coins touching and leave a fair amount of room between them. Remember you will be staking the coins 2 per slot.

Step 5: Cut It Out

Cut the coins out. It is harder to slice cardboard like this so I used a stabbing motion around the coin. repeat for the rest. Keep it tight or else the coins will fall out when you place it in the slot. It is easy to cut more out, but it is harder to start over.

Step 6: Done

Once you have all the coins cut place your coins in the holder and place your holder in your wallet. When you are at the local eatery you can know you have the correct change.

Note: When you are waiting in line, it is a good idea to punch out the coins and have them all ready in your hand.

1 Person Made This Project!


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67 Discussions


2 years ago

Nahh..ten dimes at all times.. Lightest & smallest.


3 years ago

Here is another alternative...


5 years ago on Introduction

How about using 2 old credit/ATM cards stuck together but offset the holes slightly so that you can push a coin in from each side but they won't go the whole way through. That may cure the push right through issue. I may have a play and see what I can make and then post--- so many ideas/projects, so little time


7 years ago on Introduction

A paper model that uses this instructable as a basis to make another version:


7 years ago on Introduction

This is way cool! I made one with 4 pennies, 2 nickels, 1 dime, 1 quarter, and 1 half dollar.


7 years ago on Introduction

I think the FEWEST number of coins would be 9 if you replaced the two quarters with a half. Although it may not work with a pop machine.


7 years ago on Introduction

I was thinking something similar to your suggestions. I think you can use clear packaging tape to cover the holes completely on one side and about half of each of the holes on the other side. And you can dispense the coins out of the half covered circles but it would be hard for them to fall.

Ian M

10 years ago on Introduction

I've heard that when people used payphones, they would carry a quarter in these in case of emergency. Nowadays, it's probably easier to find a coin on the street than a payphone; so it's probably better to carry a payphone with you.

10 replies

an old phone. you insert a certan amount of money and then you can call someone with it.

i think there found in the city. Like New York.
i wouldnt know though I live in a neghborhood.


Reply 10 years ago on Introduction

oh yeah.... forgot to mention that the other day, I broke down and my phone was flat. I walked for quite a while looking for a payphone and ended up returning to my car, an hour and a half later, only to ask someone to use their cellphone. This was in a very populated suburb of Anaheim, CA. Long story short, compassion (which seems rare these days) is likely more frequent than a payphone.