Okay, pet peeve coming up! How do you write inches? Let’s say we’re talking about a painting that’s five and a half inches by seven and one eighth inches. Do you write 5 1/2 x 7 1/8 in? Or do you write 5.5 x 7.125 inches? I hope you write the former rather than the latter. Why? Because inches are written with fractions!
So that’s my pet peeve in a nutshell. (WARNING…some math stuff coming up…😳)
When we use a decimal point, we’re talking about numbers with a base of 10. So 0.5 is five out of 10, 0.7 is seven out of 10, 0.01 is one out of 100.
With inches, we’re talking about a base of 2 (rather than 10). Inch fractions use denominators that are powers of 2 and go up to a 64th of an inch. So fraction denominators will be 2, 4, 8, 16, 32, 64 (eg 1/2, 3/4, 3/8, 5/16, 7/32, 11/64). You can see there are no tens involved!
Think of a ruler that’s a foot long. It’s made up of 12 inches. (Still no tens to be seen!) Each inch is usually divided into 16 parts. So we can have 1/16 of an inch or 5/16 of an inch. If we have 4/16 then that fraction becomes a 1/4. If we have 8/16 that becomes a 1/2. We try to make the lowest equivalent fraction. (Remember back to math class? That may be difficult I know!) Anyway, you can see we’re talking about fractions. Not a decimal point in sight.
So when I see someone write “6.82 inches,” I think, What does that mean? What does that look like? I can’t find it on a ruler so I have no visual picture of what it is.
Centimetres on the other hand are divided into 10. A ruler will have each centimetre divided into 10 parts (10 millimetres). So if I see 6.7 cm, I can visualise that on a ruler. The decimal point shows seven out of 10 parts.
You can of course create a decimal from a fraction. Certainly, fractional inches are limited whereas decimal inches are limitless. BUT as an artist rather than an engineer or a person in construction-land, I don’t need limitless. I need a measurement I can visualise. And traditionally, inches are written with fractions and I can visually conjure these up as I’ve been brought up using inches.
So the question is, why do people write inches with a decimal point? Well it’s a heck of a lot easier that’s for sure! Just pop a decimal point in and voila!
(A side note: I bet many of those decimalised inches aren’t even correct! Want to know how to make a correct decimal out of a fraction? See the video I’ve posted at the end.)
Fractions are a right pain so it’s easy to understand that a person might want to avoid them. But the reality is, inches come with fractions!
Gawd that’s an awful lot of numbers for an art blog but I needed to get this peeve off my chest! So let’s look at a couple of images.
I’ve been preparing for our Looking at Art session in the IGNITE! Membership (where we look at paintings related to the month’s theme) and I’ve been cruising around the Art Gallery of Ontario. Measurements are written both in centimetres and in inches and each notation looks quite different – the centimetres are written with a decimal point, the inches with fractions.
Here are a couple of examples:
You’ll find that some museums give dimensions only in inches or centimetres rather than both but they’ll be written as they should be: inches are written with fractions while centimetres use a decimal point. (Some galleries note the measurements in millimetres which means no decimal point…just numbers.)
I think it would be a great idea to embrace the metric system as there are NO fractions (which are pretty ughy so it’s no wonder there’s a trend by artists to write fractions of inches with a decimal point). In the metric system, there are only whole numbers. But for some us brought up in the feet-and-inches world, it’s harder to visualise measurements in centimetres (and metres and millimetres). Still, I encourage you to move into the metric world!! I’m trying.
In the meantime, please, if writing about dimensions in inches, use fractions rather than a decimal point!
Right. That’s me off my soapbox. I’d LOVE to hear your opinions about this whole fashion of writing inches as fractions. Do you write inches with fractions or a decimal point? Let me know your thoughts!
Until next time,
PS. Here’s the Hare Study as a whole:
PPS. I got curious about the origins of the term “pet peeve.” Curious? Then click HERE.
PPPS. Here’s a great wee video on how to go from fractions to decimals and back again!