How many can you solve? Brain-flexing math riddle quiz

[Math Quiz] What number goes in the blank?

[Math Quiz] A Great Problem from the Math Olympiad Solvable by Lower Elementary School Students!

Do you know the Arithmetic (Math) Olympiad, where people around the world compete in their mathematical abilities? Here’s a fill-in-the-blank problem from the 2019 trial that lets you experience its atmosphere.

You’re given a grid with 4 rows and 7 columns.

It contains the numbers 1 through 5, but three cells near the center are blank—try filling them in.

What makes this problem interesting is that it doesn’t rely on adding or dividing numbers; it calls for a flash of insight.

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[Math Quiz] How many horse mackerels are there?

[Challenging Math Quiz] Take on the challenge for elementary students! A Japan Math Olympiad-style problem that tests your mathematical sense: 'How many horse mackerel are there?' (IQ puzzle, brain training, mental exercise)

Here’s a quiz about shopping titled “How many horse mackerels?”.

The quiz features a woman who has come to shop.

She buys at least one of each of seven types of fish and pays 3,600 yen.

What we know of the breakdown is: fish A costs 130 yen, fish B costs 170 yen, fish C costs 78 yen, and fish D costs 104 yen.

From this, let’s figure out how many of fish B she bought.

This problem actually appeared in the Math Olympiad and is quite complex.

It’s said that even among University of Tokyo students, the correct answer rate was only about 19%.

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[Math Quiz] Using 4-minute and 7-minute hourglasses, measure 9 minutes.

[Math Quiz] Using 4-minute and 7-minute hourglasses, measure 9 minutes.

It’s a simple yet tricky puzzle: using a 4-minute and a 7-minute hourglass, measure 9 minutes.

If you just use the 4-minute and 7-minute hourglasses, a total of 11 minutes would pass.

So the key to this problem is how to measure 7 minutes.

For those who are having trouble finding the answer, here’s a hint.

If you flip both the 4-minute and 7-minute hourglasses at the same time, the 4-minute hourglass will run out first.

At that point, the 7-minute hourglass will have 3 minutes’ worth of sand remaining.

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A calculation quiz where you look at the illustration and answer

[1-Minute Test] A math quiz for kids that many adults slip up on

A visually engaging calculation quiz where you answer by looking at illustrations.

In this quiz, you examine equations that combine illustrations with numbers to derive the answer.

For example, an equation might state that “adding the horse illustration three times equals 30,” and based on that, you figure out what each illustration represents in the combined equations.

For instance, if the equation is “adding the horse illustration three times equals 30,” then 30 ÷ 3 shows that each horse illustration represents 10.

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[Rule Quiz] What number goes in the blank?

[Math Quiz] A riddle you’ll want to crack in 10 seconds!

Creativity is key! This is a quiz where you guess the missing number.

You’re shown a diamond shape containing four numbers, with one number on each of the top, bottom, left, and right sides.

There are four such diamonds in a row, and in the last one, the bottom number is blank—you need to fill it in.

If you notice the pattern from the other diamonds, you’ll solve it quickly.

The trick is to create a formula using the top and the two side numbers.

It’s surprisingly simple, and once you get it, it’s very satisfying.

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