The document discusses the application of mathematics in understanding space by comparing distances and sizes of celestial objects in relatable human terms. It suggests various engaging math problems for children, such as calculating travel times to the moon using different animals and comparing the sizes of planets and moons. By framing space concepts in familiar terms, the document aims to enhance children's sense of the universe's vastness and encourage creative mathematical thinking.

1. Space maths

2. When it comes to “how many”, I can handle numbers up
to a few hundreds as they are a part of my daily
experience. For example:
•There are 365 days in a year.
•In a single day’s school visit our mobile
planetarium welcomes around 250 pupils.
•One box of spaghetti contains about 600 pasta sticks.
And so on. There are no billions in my day-to-day life.
When it comes to “how far” or “how big”, my mind goes
blank after 40 000 kilometers. That’s the circumference of
the Earth!
But let’s go back to space maths.
I like to measure distances in space not in light years, like
other astronomers do, not even in astronomical units or
parsecs, but in human years. To make sense of those
numbers I ask myself: how long will it take me to get there
by foot. Or by car. Or by plane.

3. My students always enjoy this simple math problem:
The fastest thing in the Universe is light. The light takes 1
second to get to the Moon but 100 000 years to travel
across our Milky Way galaxy. What about humans? Neil
Armstrong, the first astronaut to land on the Moon, took
about 3 days to get there. How long would it take a human
astronaut to cross the Milky Way? When the children
figure out the answer, they stop asking when we are going
to visit other galaxies. The numbers speak for themselves.
(And no, we are not going to think about complicated
orbits, gravity assist maneuvers and what nots that will
definitely affect the travel time in reality! We will let the
space flight engineers worry about those things.)
Space maths is not only a great way to practice the times
tables and play with numbers, but also an opportunity for
the children to get a sense of the vastness of the
Universe!

4. So what kind of math problems can children be working
on?
•The first problem that comes to mind is to compare the
sizes of the space objects. How many Moons do you need
to put one on top of the other so that the “Moon tower” is
as tall as the Earth? How many Earths do you need to
make the tower as tall as the Sun? And combining the
who, how many Moons will make the “Moon tower” as tall
as the Sun?
•When the children learn the concept of a volume, they
can work on the same problem in 3D. How many Moons
will fit inside the Earth? How many Jupiters will fill the
Sun?
•The variation of the first problem can be called “balance
the scale”. It involves comparing masses of different
planets and moons.

5. •Kids will definitely enjoy figuring out how long it will take
them to travel to other planets or even to the Sun riding
different animals! Golden Eagle can cover 300 km in one
hour. Cheetah, the fastest land runner, can cover 100 km
in an hour. Maybe they fancy riding an ostrich (96 km/h)?
Or a komodo dragon (20 km/h)? Or a dolphin (65 km/h)
How long will it take them to get to the Moon, which is 384
400 km away?
•The “swap around” problems give a good idea of sizes
and distances! For instance: if we place Saturn to where
the Earth is now, how far the Moon would be from Saturn?
How far the Moon would be from Saturn’s rings?
•Older children can be offered unit converting problems,
that’s a lifetime skill. The pupil asked me recently, how
many miles the light can travel in a year. My answer was:
the light travels at a speed 300 000 km per second. The
child has figured out the rest! And he could not have been
prouder of his achievement even if he measured the
speed of light himself!
So get creative and let the kids enjoy their maths!
Happy counting!