Tag Archives: lego

32 fun and geeky things to do with kids

Not only do you have to feed, clothe and generally look after the physical welfare of children. You have to entertain them as well. Kids have low boredom thresholds and short attention spans, so this is no easy task. The good news is that there are lots of things you can do that are fun for the adults as well. Here are some of the things I have done with my son (now aged 7) over the last few years. I’m interested in science and computers, so some of them are unashamedly geeky. I hope that it gives you some ideas for things to do with your own kids. Or other people’s kids (other people’s kids are the best, you can give them back when you have had enough).

Note that some of the links below are Amazon affiliate links. If you buy something, I get commission to spend on more toys! Other vendors are available.

Make a potato cannon (spudzooka)

Potato cannons are great fun. Ram a spud down the barrel, spray some butane, hairspray or similar into the combustion chamber, create a spark and WHOOOOMP. Your spud can go over 100 metres. If that doesn’t put a big smile on your face, you must be clinically dead. You can see one in action here. They are relatively easy to make. Various plans and videos are readily available on the Internet. Mine was based on these plans and the parts were sourced from the UK supplier they recommend.

make a spud cannon

Disclaimer: A potato cannon is potentially very dangerous (the clue is in the word ‘cannon’) so exercise common sense.

  • The fumes from the glue during construction are potent. Do your construction in a well ventilated area and avoid sparks.
  • Use pressure rated materials and don’t use high power fuels such as acetylene. Your spud cannon could explode.
  • The spud comes out of the barrel at great speed. Never point it at a living thing.
  • Firing the gun is definitely a job for an adult.

Learn to program

The Scratch programming environment is ideally suited for creating simple games and is a fun and free way to learn to program. Programs are constructed by snapping together colour coded blocks – there is no syntax to learn and very little typing. Within an hour children can go from nothing to having created a simple example game with graphics and sound.

programming for children

Children too young for Scratch can still play simple programming games.

Make a house from cardboard boxes

Children have a habit of ignoring expensive presents in favour of the boxes they came in. We had a load of cardboard boxes and packing tape left over from moving house. We used them to make various constructions, including a train and a house.

cardboard box playMake mega bubbles

Blowing bubbles is fun. The bigger the bubble, the more fun! We purchased a mega bubble kit. It contains a bubble wand, some instructions and the secret ingredients list for making mega bubbles (hint: include some cornflower to make the bubbles more durable).

mega bubblesDo some star gazing

Every child and adult should have the chance to gaze in wonder at the stars from time to time. Ideally do your star gazing well away from city lights, on a cloudless day when there is no moon. The very impressive Star Walk astronomy app (for iOS and Android) will tell you where the satellites, planets and stars are. The best time to spot satellites is shortly after sunset. You can use ISSTracker.com to work out when the International Space Station is passing overhead.

ISSYou can sometimes see several of Jupiter’s moons just with binoculars. If there is a full moon, look at that instead.

Tip: If you have a trampoline in your garden, that can be a comfy place to lie back and look at the stars.

Make a water slide

Water slides can be great fun, especially if you have a slope in your garden. You just need a big sheet of thick plastic, a hose pipe and some washing up soap. The Slip N Slide slides aren’t particularly well designed or made, but the plastic sheet has lasted ok.

slip n slide water slideFor the more ambitious, there are some instructions on how to make your own monster slide here.

Watch Star Wars

Star Wars is an essential part of any budding geek’s education. But I think episode 3 is too dark for a 7 year old, so we have only watched episodes 4, 5 and 6 (the best ones!) so far. More on this topic over at Scott Hanselman’s blog.

Make an igloo

If you get a good amount of snow (rare in the UK) you can make your own igloo. After a couple of attempts at this, I believe the best approach is to make ‘bricks’ by packing loose snow into boxes. Each ring of bricks being of smaller diameter than the one below. Ideally use rectangular/square boxes of varying sizes, with the  biggest ‘bricks’ at the bottom. More details here.

iglooMake something from Lego

I love Lego and I think it is great for encouraging creativity in kids. But, in becoming the corporate titan it now is, Lego seems to have lost its way a bit (particularly in their pink and pony themed ‘friends’ range for girls, ugh).

When I was a child there were few kits or different types of pieces. Mostly I had red, white and blue 2×4 bricks and I used my imagination to come up with my own designs. (Interesting trivia, apparently the founder of Lego was a pacifist and he didn’t want little boys making tanks, so that is why there were originally no green or brown bricks.) But now Lego seems to be all about following instructions and finding the right piece. I bought loads of 2×4 bricks and other basic pieces from the bricklink.com website. The website UI is a bit confusing at first, but once you get used to it, it is a great resource for buying Lego relatively cheaply. You can also buy second-hand Lego from e-bay. I just kept bidding low on job-lots and picked up a few bargains (plus one rather disgusting consignment that got sent straight back for a refund). Here is something I made recently, mostly from 2×4 bricks (I got a bit carried away).

My Lego cruise linerTip: You can wash second-hand Lego by putting it in a string bag in the dishwasher. But don’t put it on maximum temperature, unless you want a Salvador Dali effect!

If you are going to buy new kits (hard to avoid) get the Lego Creator ones, as they generally allow you to create at least 3 different models from each kit. This means better value for money and it encourages kids to pull their creations apart and make new things from them. The Crazy Action Contraptions kit is also good fun.

Play computer games

My son loves playing computer games. There are a lot of great apps for kids. Here are some of the better ones.

Pre-school kids:

Older kids:

  • Bridge constructor (iPad)
  • Cut the rope (iPad)
  • Splitter Pal (iPad)
  • Incredible machine (iPad)
  • Maths vs zombies (iPad)
  • Wipeout wall (iPad)
  • Crane Lite (iPad)

I also think the open and constructive nature of Minecraft makes it a good game for children. But, be warned, it is very addictive.

There is also a good list of ‘analogue’ games at gameskidsplay.net.

Make a scale solar system

You can make a scale model of the solar system with household items to show just how vast the solar system is. This link allows you to work out the size and distance of each planet based on the size you choose for the sun. For example, setting the size of the sun to 300mm (about the size of a soccer ball) means an earth of about 3mm (about the size of a peppercorn) at 32m. Choose the size of your sun according the items or space you have available.

Tip: If you are doing it in your garden you need either a very small sun or a very large garden!

If that isn’t mind boggling enough, try this flash simulation which goes from subatomic particles to the whole universe (requires Flash).

Watch Mythbusters

My son and I both love the Discovery Channel TV series ‘Mythbusters’. In case you aren’t familiar with the premise: the hosts try to replicate various myths to see if they hold any truth (e.g. are you safe from bullets under water?, would a penny dropped from a skyscraper kill you?). It’s basically the scientific method disguised as an entertainment show. And very entertaining it is to. If you can’t get it on your TV, you can see lots of excerpts on Youtube.

MythBustersTip: Many of the episodes are not suitable for young children (e.g. is it possible to decapitate someone with a ceiling fan?). So check them out first.

Read Peter’s Railway

Peter’s Railway is a wonderful series of books about a boy and his grandfather building a miniature railway. They combine quite a lot of science and engineering with a great story and illustrations.

Peter's RailwayLaunch a bottle rocket

  • Take an empty plastic 2 litre drink bottle.
  • Fill it about a quarter full of water.
  • Find a cork that will fit tightly.
  • Get a foot pump with a needle valve and push it through the cork.
  • Push the cork into the bottle.
  • Point the bottle rocket in the air.
  • Keep pumping until it takes off.

It can go surprisingly high and fast in a gratifying demonstration of Newton’s third law. More information here.

Disclaimer: Half a kg of water travelling at 10+ metres per second could do some damage, so be careful and make sure it doesn’t fall over during pumping.

Play trump cards

I used to play trump cards when I was a kid. In case you aren’t familiar with the concept, you have a pack of cards on a certain theme (e.g. sports cars or jet fighters) each with certain attributes (e.g. top speed or horsepower). When It is your go, you call out what you think is the best attribute of your top card. If it is better than your opponent’s top card you take his card and go again. If not he takes your card and it is his turn to choose. The game continues until one player has all the cards. The best thing about trumps is that it is teaching kids to understand numbers on the sly. It certainly helped my son to learn his numbers.

Tip: Top Trumps used to be the best brand of trump cards in my youth. Now they have gone for all sort of lame merchandising tie-ins such as Harry Potter and Star Wars. Sigh. The Ace trumps brand is better (and cheaper). Or you can go for the fantastically geeky Dr Hal’s Physics trumps.

Dr Hal's physics trump cardsPlaying 21/Pontoon/Blackjack with your kids is also a good way to improve their addition.

Play double or quits

I heard that Warren Buffet put a fruit machine in his house to teach his children about the folly of gambling. So I sometimes offer my son to play double or quits with his some of his pocket money. If he accepts, we flick the coin. If he wins I double his money and he has the option to play again. If he loses I keep his money. The first few times we played, he kept playing until he lost his money. Now he has learnt a bit about probability (the hard way) and won’t play, or perhaps just 1 flick of the coin. Result!

Tip: If they lose, don’t give them their money back. No matter how much they plead. Otherwise they will learn entirely the wrong lesson. Tough love.

Do some experiments

There are plenty of books with experiments you can do with kids at home, e.g. Do try this at home by the Science Museum.

home experimentsDig a hole

We designated our son a corner of the garden as his. He has spent many a happy hour there digging holes and filling them in. Sometimes the simplest things in life are the best.

dig a holeMake a small explosion

Most things in fine powder form will combust very rapidly (big surface area). Kids love explosions. We poured some icing sugar down a long carboard cylinder onto a tee-light candle to make a satisfying ‘whoomp’.

Disclaimer: Try this outside and entirely at your own risk.

Make a stop motion animation

It is relatively easy to make a short stop motion animation using a digital camera (ideally on a tripod) plus some toys or Lego. You can use free software, such as Windows Movie Maker, to join the stills into a movie. There are lots of videos showing how to this on YouTube, for example.

Solve a 3D maze

3D mazes are fiendishly difficult and quite addictive.

perplexus 3d mazePlay chess

Chess is great for helping kids to concentrate. Keeping it interesting for the adult can be a challenge though. I’ve tried the following to handicap myself with various degrees of success:

  • Only allowing myself a few seconds per move.
  • Starting with less pieces (e.g. no queen or no castles).
  • Allowing them to change sides part way through.

Chess for childrenDo some electronics

We bought our son the Hot Wires electronics kit and he has played with it loads. The kits is surprisingly well made, but the instructions aren’t great. They clearly show how to make 100 different circuits, but they don’t really explain how any of the circuits or components work. However my son was quickly building his own simple circuits and learning by trial and error.

electronics for childrenGo to a hands-on museum

The best museums are ones where you play with the exhibits. Our favourites are:

Watch a Youtube video

Whatever geeky things you are into, there are almost certainly some videos about it on YouTube. I particular like the Open University 60-second adventures in Astronomy series.

Tip: I strongly recommend you turn ‘Safety’ on if you are browsing YouTube with kids (or your parents, come to think of it).

Grow something

I think it is important that kids know food doesn’t appear by magic in supermarkets. Potatoes are pretty easy to grow.

grow somethingPlay a board game

My son likes Monopoly (interestingly, a game originally invented by Quakers to teach people about the evils of property ownership). All the dice rolling and money changing hands is good for his numeracy. But it is a rather brutal game that can go on forever. I prefer Ticket to ride, which he is also very keen on. This is a German-style game of strategy that can be played in an hour and you have no idea who has won until the very end.

Ticket to ride gameWe have also had a lot of fun with Cube Quest, which is a good mix of dexterity and tactics.

Do some plumbing

We had some drain pipes and guttering left over from renovating our house. Rather than throw them out we let our son play with them. He has spent many happy hours connecting them up and putting toy cars, balls and water down them.

Fly an RC helicopter

The latest remote control helicopters are amazing. I have a little Syma indoor RC helicopter that I bought for about £15. It flies amazingly well and it is still going strong after countless crashes onto a tile floor. I find it hard to believe such an amazing piece of engineering is so cheap.

remote control helicopterI also have its big brother, but I find the indoor version much easier to fly (and less dangerous!).

Have a Scalextric party

For our son’s birthday we hired some guys to set up their Scalextric track in our house. The kids had so much fun. It was unanimously declared ‘best party ever’.

Scalextric partyTip: Book an extra 30 minutes for the adults at the end!

Play Mastermind/Brain Master

My son enjoys playing this classic logic game from my youth. It can be a bit trying when you are trying to guess the colour and they score you wrong, but you can award yourself bonus marks if you can spot that have scored you wrong without seeing the code!

mastermind logic gameBuild a go-kart/gravity racer

I’m not very good at making things, apart from software. But my father is. He made my son this rather splendid go-kart. I just wish it was big enough for me.make a go kartDisclaimer: It is possible to flip a go-kart. We proved it. So do wear some protective gear.

Bonus extra

Fly a model rocket.

Your turn

What fun and geeky things have you done with kids? Please add a comment below.

The world’s fastest Rubik cube solver is made from Lego!

CubeStormer II is the fastest Rubik cube solving robot in the world. It set a Guinness World Record of 5.270s for the fastest robot solving of a Rubik’s Cube in November 2011. I saw it in action on Saturday at the Swindon Lego show. Click the image below to watch a video I took.

(there is also a .mov version on screencast.com)

The project was commissioned by ARM Holdings and designed and built by Mike Dobson (who built the Lego robot) and David Gilday (who wrote the software). A custom Android app on a Samsung mobile phone images the cube and instructs the Lego robot what turns to make. The robot is made from 4 Lego Mindstorm NXT kits.

I got to speak briefly with David Gilday and he told me that the software is optimized for the robot’s capabilities, so it computes the quickest sequence for the robot, rather than the minimum number of moves. The software uses pre-computed look up tables of moves for speed. Apparently the limiting factor on the speed is the power of the motors. CubeStormer II can manage about 5 moves per second, whereas the best humans can manage 9 moves per second.

It didn’t work every time. But it is an impressive achievement. Especially considering the software was written by a hardware engineer! ;0)

(there is also a .mov version on screencast.com)

More details over at Wired.


I loved Lego as a child. Now I have a two year old son I have a good excuse to play with it all over again. Below are some of things I have managed to construct out of Lego Duplo with his ‘help’ (building something out of Lego with a two year old reminds me of playing Tetris, only in 3 dimensions rather than 2).

What has this got to do with software? Not a lot. I am not even going to attempt a strained analogy with software design. But I figure nearly everyone interested in software also likes Lego, even if they haven’t played with it for a few decades. Am I wrong? Some of you might have preferred Meccano – but you are probably Perl programmers now. Serves you right.

Anyway, I am looking for some inspiration for future creations. A search on Google only turned stuff a bit out of my league or not very appropriate for a two year old (work safe). Have you (or your children) built anything good out of Lego (Duplo, classic, Technics, Mindstorms etc)? If so, please post a link to a photo in the comments below. Alternatively email them to me and I will add them for you.

I reserve the right to sneer at anything made by following instructions on a packet.

Photos & comments sent in:

Scott: “It may not be as involved as your creations, but my daughter absolutely loved this crane that I made.”

Bob: “I have many happy memories of building LEGO projects with my son who is now studying Computer Aided Product Design in college. He started out with bricks, then Technics, and then MindStorms. I think the LEGO people should be commended for having made some excellent products over the years.”

Stephen: “Like you, I also had Lego when I was a kid. Meccano, I did not have.
I could never afford too much Lego, so had to settle for one railway
engine and a really small amount of track to go with it. The things I
buy my nephews are much more involved. Quite a change.

Anyway, some tidbits of Lego info for you. The moulds for the bricks are
machined from tungsten carbide using diamond cutting bits and machines
the moulds to 1 millionth of an inch accuracy. My uncle’s company wrote
the CAD software that controlled the CAM machinery for this operation.
That info is I guess, now about 20 years old. I’ve no idea if they still
make them the same way, But apparently that is how they did it back then
(assuming my memory hasn’t tweaked any details). I was always told it
was 1 millionth of an inch but that may have been for explanation’s sake
and they may well have measured in microns, fractions of a millimeter. I
guess stepper motors are your friend for this type of job.

The bit I love is that the moulds are made out of something so
tough they have to use diamonds to cut them. And all for some
lightweight plastic bricks!”