How many children are there in the world? Try our kids’ quiz

1. Zain, 6, asks: how many children are there in the world?

   1. 1 billion

   2. 2 billion

   3. 3 billion

   4. 4 billion

2. William, 8, asks: what is the world record for solving a standard Rubik’s Cube?

   1. 2.13 seconds

   2. 3.47 seconds

   3. 4.24 seconds

   4. 12.22 seconds

3. Ethan, 5, asks: how many legs does a centipede have?

   1. Centipedes always have 100 legs – the “cent” in their name stands for 100

   2. Centipedes always have 1,000 legs

   3. More than 100 but less than 200 legs

   4. They have between 30 and 400 legs

4. Esther, 6, asks: how big can tortoises get?

   1. Up to 1 metre in length

   2. 1.5 metres

   3. 2.5 metres

   4. Some tortoises have measured 5 metres long

5. Arlo, 6, asks: would all of the bacteria in the world be able to fit in a rucksack?

   1. Yes, of course, bacteria are very tiny so they could easily fit into a rucksack

   2. Absolutely not

   3. Only if it was quite a big rucksack

   4. If you were able to gather them all up together and herd them into one place, then you could fit them into a regular rucksack

Solutions

1:B - There are approximately 2 billion children in the world between the ages of zero and 14., 2:B - The world record to solve a single 3x3x3 cube is 3.47 seconds! It was set by Yusheng Du at the 2018 Wuhu Open competition in China., 3:D - Despite the name indicating that they have 100 legs, centipedes can be all sorts of different sizes and have different numbers of legs – one set on each body segment. The smallest number is 30, or 15 pairs of legs., 4:B - Galápagos tortoises, or giant tortoises, are the biggest species of this animal. Some of the largest ones have grown up to 1.5 metres – about the height of a short-ish man! , 5:B - Bacteria are tiny but they are almost everywhere! Most of them live in the ground or in water, but many also live inside or on the skin of other organisms, including humans. Even if you got them all in the same place, the biomass – the mass of living organisms – of all the bacteria in the world is estimated to be more than a thousand times bigger than the biomass of humans!

Scores

1. 5 and above.

2. 4 and above.

3. 3 and above.

4. 2 and above.

5. 0 and above.

6. 1 and above.

Molly Oldfield hosts Everything Under the Sun, a weekly podcast answering children’s questions, out now as a book.

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