
If a notebook costs 100 yen, 20 yen cheaper than a pencil case, then how much is an eraser?
I’ve never been all that good with numbers, but word problems in particular were pretty troublesome for me. I mean, if a train leaves from Detroit at 9:45 going 80 miles per hour in a south-by-south-westerly direction and another train leaves from Nashville 570 miles away at 10:03 going 87 miles per hour, what are the chances that they will suddenly implode so I don’t have to solve for x?
At least that problem does (apparently) have an answer, but we’ve found one math problem that’s completely stumped the internet:
https://twitter.com/__zero____/status/671528177991192576“Baffling…”
The first problem reads:
“A notebook is 100 yen, 20 yen cheaper than a pencil case. How much is an eraser?”
Japanese netizens were just as perplexed as we were, commenting:
“What madness is this?”
“There is no answer (grin)”
“Who is the genius who thought this up?”
“Market value!!( ಠωಠ)”
“This is… philosophy!”
“For a second I thought, ‘What? Too easy lol.’ I kinda wanna kill myself.”
But how about that second problem? Maybe it’s a little easier? Let’s see:
“A sandwich is 98 yen, 10 yen cheaper than an anpan (red bean bun). How much is the anpan?”
At first glance, this one seems to be a lot easier to solve, until you notice the difference in spelling between あんぱん, anpan written in all hiragana, and あんパン anpan, written half in hiragana and half in katakana, which then begs the question: “Is there a difference between あんぱん and あんパン?”
Do be sure to let us know if you have the answers!
Source: Twitter/ @__zero____ via Hamusuta Sokuhou
Top image: Twitter/ @__zero____

Supposedly simple math homework for Japanese elementary kid stumps gamer dad, with good reason
Japan reportedly adding Japanese language skill requirement to most common foreigner work visa
Schoolkids learn life skills through shopping field trips at street markets in Kochi Prefecture
Pokémon and Ikea Japan cross over into each other’s worlds with collaboration events
Foreign man arrested for walking on Shinkansen tracks, claims he was on the run from yakuza
Japanese manhole lid raises eyebrows with fertility god symbol that looks like… well, you know
How to take your home ramen to the next level by making your own chashu pork in a frying pan
Manga is More than Just Reading, It’s a Cultural Experience – Expo 2025 with The Seven Deadly Sins
Japanese kindness restores our faith in humanity after a highway bus accident in Tokyo
The results are in! One Piece World Top 100 characters chosen in global poll
Japan considering raising international traveler departure tax even more than previously reported
Starbucks Japan closing only Shinkansen platform branch for popularity-triggered renovations
Two food hacks take Japan’s convenience store fried chicken to amazing new sandwich heights
You can assemble a well-balanced team of Pokémon, them eat them, thanks to Japanese cake chain
Fading Tokyo – Searching for signs of the Showa era as local neighborhoods evolve[Photos]
Pokémon lacquerware series expands for Year of the Horse with new handcrafted design[Video]
Tokyo turns its phone booths into free Wi-Fi hotspots, and here’s how to use them
Tokyo teahouse serves up a sakura matcha dessert you won’t find anywhere else
Totoro Fund line of beautiful artwork and apparel lets you help the real-world Totoro Forest
Japan now has a special desk for people who work at home with a pet cat[Photos]
Famous Tokyo cherry blossom spot installs view-blocking screens to fight overcrowding[Video]
Uniqlo announces new T-shirts for One Piece, Naruto and more for manga publisher’s 100th birthday
Train station platform ramen store closes its doors on half a century of history in Tokyo
Starbucks Japan releases new My Fruit³ Frappuccino at only 34 stores around the country
Studio Ghibli releases Catbus pullback keychain that runs like the anime character
Krispy Kreme releases Super Mario doughnuts in Japan for a limited time
Japanese onsen egg maker from 100-yen store Daiso needs to be on your shopping list
Survey asks foreign tourists what bothered them in Japan, more than half gave same answer
Japan’s human washing machines will go on sale to general public, demos to be held in Tokyo
Starbucks Japan releases new drinkware and goods for Valentine’s Day
We deeply regret going into this tunnel on our walk in the mountains of Japan
Studio Ghibli releases Kodama forest spirits from Princess Mononoke to light up your home
Starbucks Japan releases new sakura goods and drinkware for cherry blossom season 2026
Japan’s newest Shinkansen has no seats…or passengers [Video]
Major Japanese hotel chain says reservations via overseas booking sites may not be valid
Put sesame oil in your coffee? Japanese maker says it’s the best way to start your day【Taste test】
No more using real katana for tourism activities, Japan’s National Police Agency says