3 yen

It is said that it costs about 3 yen to produce a 1-yen coin. This is because the total includes the cost of aluminum, as well as the machinery, labor, energy, and other expenses required in the manufacturing process. Although it appears to be worth only 1 yen, in reality it incurs a higher cost.

To use as a reference for the robber's height

One reason potted plants or other noticeable objects are placed at bank entrances is for security. If a robbery or other incident occurs, the suspect’s height captured by security cameras can be more easily identified by comparing it to the height of the plants or other markers. Plants may blend in naturally and not stand out, but they actually serve a role as a security measure.

continent

The five rings that symbolize the Olympics represent the five continents of the world: Africa, the Americas, Asia, Europe, and Oceania. The interlocking rings also embody the hope that countries around the world will come together as one to enjoy sports.

Cookie

Archaeological excavations have revealed that in the Jomon period, simple baked treats made from ingredients like wheat flour and acorns existed. Because their shapes and methods of preparation resemble modern cookies, they are sometimes called “Jomon cookies.” Although they were not as sweet as today’s cookies, it’s interesting that similar techniques were already appreciated back then.

So that we can escape immediately when an accident occurs

In science labs, dangerous items like fire and chemicals are sometimes used during experiments. Therefore, backless stools are used so that, in the event of an accident, students can immediately stand up and escape. With a backrest, the body can get caught and prevent quick movement, so the use of backless seats is a safety measure.

Japan

Instant ramen was developed by Momofuku Ando of Japan. It began in 1958 with the creation of the world’s first product under the name “Chicken Ramen.” Inspired by postwar food shortages, it was born from the desire to make ramen that anyone could enjoy easily, safely, and deliciously—and from there it spread around the world.

18 pieces

Cats have five toes on each front paw and four on each hind paw, for a total of 18 toes. We often imagine the same number on the front and back paws, but in reality there’s a difference to help them climb trees and grasp objects.

black

When we think of blackboards, we often picture them as green nowadays, but they used to be black. It’s said that black was the standard because blackboards were originally made from black stones like slate. Chalk for blackboards is typically white, and white writing was easiest to see on a black surface, so black was the norm at the time. However, green blackboards came to be widely used because they’re gentler on the eyes and easier to see during class. You can still sense a trace of their former color in the name “blackboard.”

female

Among mosquitoes, only the females need blood. Females obtain the nutrients required for egg laying from the blood of animals. Therefore, males, which do not lay eggs, have no need to suck blood. Also, females usually feed on nectar and plant juices just like males do.

42.195km

The marathon originally derives from a Greek soldier who supposedly ran from Marathon to Athens to report victory, and it used to be run under a rule of about 40 km. However, starting with the 1908 London Olympics, the official distance was set at 42.195 km. It seems that this decision was influenced by a request from Queen Alexandra of the United Kingdom.