A multiple-choice quiz with three options for upper elementary students. Fun questions that build thinking skills.

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 It’s said that black was the standard because blackboards were originally made from black stones like slate.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.

hermit crab

The king crab is a quintessential taste of winter. If you ask what kind of creature a king crab is, most people would say it’s a crab. But in fact, it’s related to hermit crabs. Although it closely resembles crabs in appearance, unlike true crabs, two of its legs are tucked inside the carapace, so at a glance you only see eight legs. Also, unlike crabs, king crabs can move vertically.

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.

Denmark

LEGO is a Danish toy company founded in 1932. The founder is Ole Kirk Christiansen. I think everyone has seen the toys known as LEGO bricks at least once. Collaborative products with films and games—such as the Star Wars series and Minecraft—are also very popular.

foreleg

A cricket’s ears are located in a completely different place from human ears. A cricket hears with structures called tympanal organs on the shins of its front legs, using tiny openings there to detect sound. It’s a fascinating fact that shows how the bodies of living creatures can be built differently.

Effect of meals

Flamingos are pink mainly because of what they eat. They consume foods rich in pigments, such as shrimp and plankton. These foods contain carotenoids—red and orange pigments—which, when absorbed into the body, cause their feathers and bodies to turn pink.