I am teaching a fairly rowdy class of Year Nines (fourteen-year-olds) how to do average speed calculations.

Halfway through an explanation, one of the kids puts his hands up. 

Student: “Miss, I have a question!”

Me: “Okay, what’s up?”

Student: “If the shop is two miles away, and people walk at three miles an hour… why has it taken my dad seven years to go buy his tabs [cigarettes] and he’s not back yet?”

I lasted three seconds before I cracked up.

His dad still lives at home; the kid just likes to wind me up!

Client: “We’d like you to design some labels for our new products.”

Me: “What size are the labels?”

Client: “They’re for three 250g jars.”

Me: “…”

Client: “…”

Me: “So, the dimensions of the labels are?”

Client: “250g.”

Me: “…”

Client: “Oh! Sorry! 250g probably doesn’t tell you enough.”

Me: “Haha, yeah, I need to know length and width, or—”

Client: “‘250g’ means ‘250 grams.'”

Me: “…”

I sell products to a customer. She pays, but then she calls me a half-hour later.

Customer: “You overcharged me by $20!”

I redo the math twice.

Me: “I checked twice and you were charged the correct amount.”

Customer: “Well, I didn’t actually do the math or anything. I just thought you charged me $20 extra.”

Related:
Math Is Your Friend, Part 8
Math Is Your Friend, Part 7
Math Is Your Friend, Part 6
Math Is Your Friend, Part 5
Math Is Your Friend, Part 4

I manage a women’s clothing store. We have a big sale one day, offering 50% off everything, which is very unusual. Throughout the store, we’ve placed black signs that say, “50% off your entire purchase”. To signify the clearance section, we use red signs that say, “50% off”.

A customer comes up to the register with armloads of clothes. I ring her up and give her the total, which is ridiculously low for the amount of clothing she is getting.

Customer: *Dumbfounded* “No, you made a mistake. The clearance items are free.”

At first, I think she is joking with me, but no.

Customer: “I get two discounts of 50% each on all the marked-down stuff. The signs are different colors. I should get both colors.“

Customer: “Can you break this pack of cube steak down? I only need two-thirds of a pound.”

Me: “No problem!”

I break it down as requested.

Me: “Here ya go. It’s .68 of a pound.”

Customer: “I wanted two-thirds of a pound.”

Me: “Two-thirds is .66; this is .68.”

The customer looks disappointed and shrugs.

Customer: “That’s okay. I guess we’ll just have leftovers.”