Super Safi’s Monday Morning Math Mayhem 30 – Imperial Units for Weight

Morning Mathematical Monsters & Maniacs!

(Today’s post is sponsored by the letter “M”)


Hi, I’m Super Safi and you may remember me from such stats and strategy posts as Kwik-E-Mart Farming and the advanced losing-to-win Superheroes battle strategy.

Over the past 600+ episodes, The Simpsons has taken us on an amazing mathematical journey involving fractions, probability, Fermat’s last theorem, and hundreds of other aspects from the wonderful world off mathematics.

And what better way to start your week, then by discussing math Monday morning?

This week we go back to an episode of The Simpsons from 26 years ago and look at the Imperial Units for mass.


In Whacking Day (Season 04, Episode 20), while Homer is at home preparing for Whacking Day, Lisa returns from school and has the following exchange with her dad:

Homer [to Bart and Lisa]: Hey Kids, how was school?

Lisa: I learned how many drams in a pennyweight.

So let’s look at how many drams in a pennyweight.


Imperial Units

In the 19th century, the UK was using many different systems for weight measurements, the three main of which were the Troy weight system, the Avoirdupois weight system, and the Apothecaries weight system.

As discussed last week, the Weights and Measures Act of 1824 was the first act for ascertaining and establishing uniformity of weights and measures and is considered the origin of Imperial Units.

The Weights and Measures Act of 1824 established the Troy weight system as the standard. However, the Weights and Measures Act of 1855 established the Avoirdupois weight system as the standard. Both systems use the pound as the fundamental unit, with the other units as fractions or multiples of the pound.

The Troy weight system had 4 units of weight – Troy pound, Troy ounce, Pennyweight, and Grain.

The Avoirdupois weight system had 8 units of weight – Grain, Dram, Ounce, Pound, Stone, Quarter, Hundredweight, and Ton.

From the info above, we can learn what Lisa learned, how many drams in a pennyweight. The Dram is equivalent to 27.34375 grains, while the Pennyweight to 24 grains. Therefore, the correct answer is 27.34375/24, or 1.139322916666666666666666… Dram in a pennyweight.


Now that we’ve completed a look at imperial units for weight, why not show your love for math and units with your own Math Mayhem shirt or hoodie.

If you love math or enjoy reading these posts, don’t forget to stop by the Addicts Shop and check out all the paraphernalia, including the Math Mayhem shirts and hoodies.

Were you familiar with drams and pennyweights? What’s your favourite unit of weight? Do you recall the episode from 26 years ago? Did you recall it not only features the whacking of snakes, but also these units of weigh? Sound off in the comments below. You know we love hearing from you.

8 responses to “Super Safi’s Monday Morning Math Mayhem 30 – Imperial Units for Weight

  1. My car gets 40 rods to the hogshead and that’s the way I likes it.

  2. Suddenly, the Metric system seems exceedingly simple!

  3. Can you calculate when the Christmas update will start or when it will snow lol ☃️⛄☃️⛄☃️⛄⛄☃️

  4. Thank you Safi.

    Now how many troy pounds in the other type of pounds (I’m not even going to try to spell that)?

    Next question, how many British pounds in a troy pound of gold?

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