
Stupidly rigid rules dangle down to infuriate older brother.
Between the emphasis Japanese society puts on formal education and the competitive admissions systems which often require students to take grueling entrance exams, there’s an intense pressure on kids in Japan to arrive at the right answers in their classwork. Things get even worse, though, when you add in the baffling requirements some schools have regarding how pupils arrive at them.
Japanese Twitter user @yomos1354 has a younger, elementary school-age brother, who recently brought home his graded math test. In one section, he managed to get all 10 questions wrong, which would ordinarily be pretty troubling, since they were all simple addition problems involving pairs of single-digit numbers.
But then @yomos1354 took a closer look, and realized that it’s not his brother who’s dumb, but his school.
https://twitter.com/yomos1354/status/1061965466325798912Among his brother’s responses that were marked wrong were “9+3=12” and “7+4=11.” Now, it’s true that mathematics-related linguistics often work differently in Japanese and English, but the actual phenomena of addition is universal, so what was the problem?
If you look at the first question on the test, you’ll see a note, written in red, from the boy’s teacher, which reads “sakuranbo keisan,” or “cherry calculation.” Cherry calculation is a method taught in some schools that gets its name from the annotations kids are supposed to make on their paper, which resemble a pair of dangling cherries.
For example, let’s take a look at how the cherry calculation would go for adding 7 and 4.
To start, the student is supposed to look at the first number in the problem and ask how much needs to be added to it to get to 10. In this case, we need another 3 to get from 7 to 10, so the next step is for the student to break off 3 from the second number in the problem and write it below.
Then the student subtracts 3 from 4 and writes the difference next to the 3.
Now having filled in both “cherries,” the student completes the calculation by acknowledging that the first number from the original problem plus the first cherry equals 10, and then using the number in the second cherry for the value of the ones-digit, giving the final answer of 11.
In all fairness, it should be recognized that the cherry calculation works. Performed properly, it produces the correct answer. However, there’s no getting around the fact that it replaces a single computation with four, and also requires the problem-solver to mix two types of computations, subtraction and addition.
▼ Standard computation
▼ Cherry computation
More than one online commenter asked if perhaps the class had been instructed to show their work using the cherry calculation method, but @yomos1354 says there’s no such directions written on the test, nor were the students verbally told to do so.
Of course, no one would have gone to the trouble to develop and teach the cherry calculation method if it didn’t have any possible benefits. Proponents say it can be an effective way to help young learners get over mental hurdles about how exactly arithmetic works. If a kid is completely stumped as to how to go about solving the question “7+4=?”, the cherry calculation is a method by which a teacher can give a helping hand without just solving the problem for him. “OK, how many more do we need to add to seven to get to 10?” the teacher might ask. Once the student has taken that step, the next questions would be “And if we take three away from four?” and “And what’s 10 plus 1?” This breaks the question into smaller chunks that might be easier for a child’s mind to grasp if he’s having trouble understanding the concept of how the ones-digit wraps back around to zero each time the tens-digit goes up an integer.
But all that just makes @yomos1354 even more frustrated about how his brother’s test was graded. The cherry calculation is supposed to provide assistance for those students who can’t do the calculations in their head or all in one simple step. His brother is already clearly proficient enough to not need to rely on drawing little cherries under the problems. “Not even funny how he got marked down,” @yomos1354 tweeted. “The school has no business forcing everyone to use the [cherry calculation] method for problems that are this simple,” understandably upset at how forcing his brother to use an educational crutch he doesn’t require would be hobbling him intellectually.
It’s another frustrating example of how students can sometimes get penalized for being ahead of the game in Japan, so hopefully next year @yomos1354’s little bro will be lucky enough to end up in a class taught by one of Japan’s awesomely flexible teachers instead.
Sources: Twitter/@yomos1354 via Jin, Shogakko Nyugaku Joshi no Mama Nikki, Print Kids
Top image: Pakutaso (edited by SoraNews24)
Insert images: SoraNews24
Follow Casey on Twitter, where he wrote this whole article with Ai Otsuka’s “Sakuranbo” stuck in his head.






Strap on your thinking caps for an extra-dumb, hypocritical Japanese teacher correction
Japanese elementary school kid says 12 x 25 = 300, teacher doesn’t say he’s answered correctly
Japanese student told they will be penalized for not using a ruler to draw multiplication lines
“5 + 9” is okay but “9 + 5” is wrong? Is this being logical or overly picky?
Japanese elementary school student teaches us how to solve a difficult maths problem
Starbucks Japan unveils new sakura cherry blossom collection for hanami season 2026
One Piece creator has hidden secret of anime treasure’s identity in chest at bottom of real-world ocean
Is Tokyo Station’s startlingly expensive wagyu bento boxed lunch worth its high price?[Taste test]
Is Starbucks Japan’s new Hinamatsuri Girls’ Day Frappuccino suitable for adults?
Jiggly yellow pear, Funasshi, named top mascot in Japan
Do you know what this caterpillar-like food is? We had no idea!【Taste test】
Starbucks Japan reveals new sakura cherry blossom drinkware range for 2020
Drift ice in Japan is a disappearing winter miracle you need to see now
Japan Extreme Budget Travel! A trip from Tokyo to Izumo for just 30,000 yen [Part 2]
Starbucks Japan releases the new Soupuccino, but is it everything it’s cracked up to be?
Starbucks Japan releases first-ever Hinamatsuri Girls’ Day Frappuccino
Japanese restaurant chain serves Dragon Ball donuts and Senzu Beans this spring
Japan Extreme Budget Travel! A trip from Tokyo to Izumo for just 30,000 yen [Part 1]
Japan’s craziest burger chain takes menchi katsu to new extreme levels
Japanese drugstore sells onigiri at pre-stupid era prices, but how do they compare to 7-Eleven?
Viral Japanese cheesecake from Osaka has a lesser known rival called Aunt Wanda
Lawson adds doughnuts to its convenience store sweets range, but are they good enough to go viral?
Japan’s newest Shinkansen has no seats…or passengers [Video]
Starbucks Japan releases new sakura goods and drinkware for cherry blossom season 2026
Foreigners accounting for over 80 percent of off-course skiers needing rescue in Japan’s Hokkaido
Super-salty pizza sends six kids to the hospital in Japan, linguistics blamed
Starbucks Japan unveils new sakura Frappuccino for cherry blossom season 2026
Foreign tourists in Japan will get free Shinkansen tickets to promote regional tourism
The 10 most annoying things foreign tourists do on Japanese trains, according to locals
Take a trip to Japan’s Dododo Land, the most irritating place on Earth
Naruto and Converse team up for new line of shinobi sneakers[Photos]
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
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
Don’t like trigonometry? Then you’re just like Hitler, says Japanese high school English teacher
Supposedly simple math homework for Japanese elementary kid stumps gamer dad, with good reason
Japanese elementary school teachers may tell you “5 x 100 = 500” is wrong
Japanese teacher beats up student for making fun of his body by calling him anime character name
Japanese elementary teacher busted for hiding students’ shoes, writing “die” on their belongings
Japanese teacher has student make written apology for farting in class, displays it in classroom
Students hospitalized after eating teacher’s homemade yogurt in Nagoya
Japanese teacher apologizes for peeing on students’ futon during club retreat
Nintendo to give Labo kits to U.S. elementary schools, but not Japanese schools. Why?
Japanese schoolteacher losing job for misconduct after being caught in convenience store…working
Elementary and junior high students speak out on Japan’s strangest school rules
Japanese junior high school girl removed for class from three days for grooming her eyebrows
Teen gets perfect score on Japan’s college entrance history exam with crazy-detailed notes【Pics】
“Hate summer homework, kids? We’ll do it for you!” A disturbingly booming business in Japan