I Was Speaking English

London, England, the host city of this year's International Mathematical Olympiad.

Over the past few days, math olympiad teams from more than a hundred countries around the world had arrived in London one after another.

Greenwich Mean Time was eight hours behind the time in the Chinese Capital. The Chinese Mathematical Olympiad National Team had arrived in London three days early, leaving time to adjust to the time difference.

The British hosts had arranged for the Chinese team to stay at a hotel near Waterloo Station. It was not far from the University of South Bank, London—less than a ten-minute walk away.

The team leader, deputy leader, coaches, translator, support staff, and all six team members were satisfied with the accommodations. The hotel wasn't luxurious, but it was clean and comfortable, and it was also very close to the IMO venue, the University of South Bank, London.

Shen Qi and Zhou Yu'an shared a room. They had both made it to the end and been selected for the six-person official roster of the Chinese Mathematical Olympiad team.

The two young men were about the same age and full of energy. It was their first time in Britain, and they had no intention of adjusting to the time difference. After dropping off their luggage at the hotel, Shen Qi and Zhou Yu'an headed out to explore together.

Of course, they didn't dare go too far. They just wandered around near the hotel, keeping within a three-mile radius.

As soon as they stepped out of the hotel, Shen Qi spotted something that shocked him.

"Hey, Zhou Yu'an, look at this. My English isn't great, but I recognize every word on that sign. Unless I'm mistaken, there's no way they'll sell even a single box of strawberries." Shen Qi stopped in front of a supermarket on Waterloo Street.

A sign stood outside this Tesco, with the following written in English: "Today's Special: Strawberries, £1 per box; £3 for two boxes."

Zhou Yu'an's English was pretty good. He quickly understood the offer, thought for a moment, and said, "Maybe the British use some mysterious, special number system where three comes right after one, with no two in between."

"Haha, Zhou Yu'an, that really got me. I'd rather believe it's a typo. Come on, let's go inside and take a look." Shen Qi pulled Zhou Yu'an into the supermarket.

After wandering around the store for a few minutes, Shen Qi keenly noticed that "Strawberries, £1 per box; £3 for two boxes" didn't look like a typo made by the supermarket's promotions manager.

One shelf was stocked with chocolate products, including Hershey's Chocolate, which was on sale. The supermarket's promotional sign read: "HEYSHEY'S—30%-off, Pound Sterling 18.5."

"Hey, hey, Zhou Yu'an, look! Hershey's Chocolate is normally £15 a box. Thirty percent off means 70% of the original price, right? So it should be £10.50 a box. What the heck is £18.50?" Shen Qi fell into deep thought.

After thinking it over, Zhou Yu'an said, "Does this store want to go out of business? Are they trying to keep customers away?"

Watching the steady stream of local customers coming and going, Shen Qi shook his head. "But that's clearly not the case. Look, this supermarket is packed. Business is booming. What I don't get is, people are actually buying the strawberries and Hershey's—and quite a lot of them!"

Zhou Yu'an closely observed a checkout nearby. An English woman had just bought eight boxes of the promotional strawberries, priced at "£1 per box; £3 for two." She looked delighted, as if she'd landed the bargain of a lifetime.

After the woman paid, a blond young man plunked four boxes of Hershey's Chocolate onto the checkout counter and grinned happily.

Shen Qi and Zhou Yu'an looked at each other, speechless.

"I'm afraid... the people in this area are all idiots," Shen Qi concluded.

"Obviously, this is a rip-off, and all the customers are idiots." Zhou Yu'an nodded, agreeing with Shen Qi's hypothesis.

"London: financial capital, fashion capital, football capital, and capital of fools?" Shen Qi came up with a second hypothesis.

"It's also possible that Londoners are generally rich. After all, it's the capital of the Empire on which the sun never sets. Rich fools are nothing unusual." Zhou Yu'an added a supplementary hypothesis to Shen Qi's.

"The Mathematical Olympiad—the Olympics of the Mathematics Community, an intellectual competition for people with high IQs. Zhou Yu'an, tell me, why would they hold it in the capital of fools?"

"Maybe it's to highlight... the contrast?"

The two Chinese young men strolled among the white, Black, and Indian people, marveling at the wonders of the world. They felt their trip had been worthwhile just for the chance to see something new.

"Zhou Yu'an, since we're already here, we can't go back empty-handed. Let's buy something. After all, it's a British product." Shen Qi picked up a shopping basket and wandered from aisle to aisle, taking some snacks from the shelves.

Zhou Yu'an was more frugal. He bought just one tube of toothpaste and held it in his hand. "When I came through customs, the British confiscated my Zhonghua Toothpaste, treating it like a dangerous biochemical substance. I need to buy a tube to get by for a few days."

"Give me the toothpaste. I'll pay for it all together." Shen Qi took the toothpaste from Zhou Yu'an and put it in his basket.

They queued up at the checkout, waiting to pay.

A few minutes later, they reached the cashier, and Shen Qi put his shopping basket on the counter.

"Hello," the cashier said in English. She was a young red-haired white woman.

"Mm." Shen Qi nodded and said nothing.

The cashier quickly took each item out of the basket and scanned it. The total displayed on the checkout computer was £33.50.

"That's £33.50," the cashier said to Shen Qi.

"What?" Shen Qi looked confused.

"Thirty-three pounds... fifty pence." The cashier repeated herself, speaking more slowly.

Shen Qi said to Zhou Yu'an, "I bought a box of biscuits for £5.80, a muffin for £4.60, three doughnuts for £5.40, and five bags of crisps. Each bag costs £2, and buying five gets you a 20% discount. Add Zhou Yu'an's £2.20 toothpaste, then the 7% sales tax, and I should owe £27.82, not £33.50. There's no way to calculate it and get £33.50."

"That's right. It's £27.82," Zhou Yu'an said, having also worked out the total in his head in no time.

"Hey, young gentlemen, would you like these items?" The cashier saw Shen Qi and Zhou Yu'an muttering to each other for ages. Since she couldn't understand Chinese, she reminded them, remaining patient.

"Sorry about that," Shen Qi said to the cashier. Then he turned to Zhou Yu'an and said, "Your spoken English is much better than mine. Tell the red-haired young lady what I just said about the prices, and translate it into English."

"OK." Zhou Yu'an nodded, then said to the cashier in English, "Ma'am, I think you've calculated our total incorrectly."

The cashier shook her head firmly. "That's impossible. The computer calculated it."

Zhou Yu'an rattled off the itemized prices in one breath, his spoken English extremely fluent. "One box of biscuits for £5.80, one muffin for £4.60, three doughnuts for £5.40, one tube of toothpaste for £2.20, and five bags of crisps with a 20% discount, making £8. Add the 7% sales tax, and the total comes to £27.82. We believe that's a reasonable and correct amount."

The cashier was instantly stunned. "Y-you said what?"

Zhou Yu'an was also stunned. "I was speaking English. Don't you understand?"