Measuring money: How to use dollar bill length as a ruler

Here’s a nifty trick when your kids need to measure something fast. Dollar bills make easy measuring tools. To help teach proportions and measure things on the fly, try some of these fun learning activities with your kids. Here are some of the best ways to use dollar bill length as an impromptu ruler. 

The basics: Stats on the dollar bill

Before we jump into the nitty-gritty of using a dollar bill as a ruler, it's essential to understand what we're dealing with and why it can be a useful measurement tool.

• The standard dollar bill length is roughly 6.14 inches or about half a foot. This makes it a convenient and easy-to-use measuring tool.

• The width of a dollar bill is around 2.61 inches, which can also be used for measurements in a pinch.

• The thickness of a dollar bill is about 0.0043 inches

How to measure with dollar bills

1. Lay the dollar bill flat on the object or surface you want to measure.

2. Align one edge of the bill with one end of the object. Explain to your child how important it is to line up the edges for accuracy.

3. Remember to take into account any gaps or overlaps between the dollar bill and the object being measured.

4. If measuring smaller objects, fold a portion of the bill to make a smaller unit of measurement.

Using dollar bill length to measure familiar objects

Let's put the theory into practice with everyday objects you can measure with a dollar bill. This exercise helps familiarize kids with the concept of measurement and encourages a practical understanding of the size of everyday objects. These might seem like tiny skills, but they can add up to more math-savvy kids. Let's get measuring!

• Hands and feet

You won't always have a dollar bill around, so when you do, you can use it to help kids learn proportions and improve spatial awareness. Show them how big the dollar bill is compared to their hands, feet, or arms. Then, put the dollar bill away and challenge your kids to use their new skills to find 6-inch objects.

• Credit card

We live in a digital society where dollar bills and coins aren't always part of our daily lives. Give another handy measuring tool by comparing the length of the dollar bill to the length of their debit card, library card, or school ID. Now, they have two easy measuring hacks.

• The screen of an iPhone 13 Pro Max

Fun fact: The screen of an iPhone 13 Pro Max is almost exactly the same length as a dollar bill. At 6.1 inches, it’s a near-perfect match for our dollar bill length. Try putting that in your wallet. 

• A book

Kids books come in all shapes and sizes, so they can present the perfect measuring challenge. Have your kids gather up their favorite books then use the dollar bill to measure the length and width of a book or even its thickness. This helps kids understand how measurements work in three dimensions.

Turn learning measurements into a fun game. You might be surprised how quickly they pick up on the concept. Encourage your kids to find objects around the house that match the length of the bill. Get more cool tips on kids, parenting, and more at the Greenlight Learning Center.