Review: Letterbox Lab Investigate Box 3 – Magnetoslime

We love Letterbox Lab, and the third in the series, Magnetoslime, sounds extremely exciting! I mean, magnets and slime? Who doesn’t love those?

Letterbox Lab Review Investigate Box

Letterbox Lab is a monthly box of fantastic science experiments for kids. There are two stages: the Explore Box for kids age 6+ (see our reviews here) and the Investigate Box, aimed at children age 8 – 12.

Little C is eight, and we’re now working our way through the Investigate Box series that the lovely Letterbox Lab people are kind enough to send us!

Letterbox Lab Review Investigate Box

There are seven experiments this month, all conveniently bagged up and labelled. There are also some extra goodies!

The booklet has full instructions for all the experiments, suggestions for further exploration, and excellent safety prompts. Cartoon guides Meg and Pico (above) help children through all the stages, and give great encouragement for asking questions and thinking. There is also a parent/grownup guide so you know exactly what your little scientists are going to be doing.

OK, let’s take a look at some of the experiments.

Letterbox Lab Review Investigate Box

Slippery Slime

You get everything you need to make ooey gooey slime!

Cornflour, shampoo, food colouring, and gloves. OK, we didn’t use the gloves because it’s far too much fun using your hands. Mixing it was actually quite hard work, but the results are excellent.

Letterbox Lab Review Investigate Box

Amazing, right?

Now, not only is this slime fun to play with, it also has a really interesting property – it hardens when you apply pressure. This is one reason why mixing it is hard work. It goes goopy when you let it run off your hands, but squeeze and it becomes solid.

This is called a Non-Newtonian Fluid, and this slime is a really cool way for kids to learn about it.

Letterbox Lab Review Investigate Box

Cloud in a Bottle is really pretty.

Mica powder shaken in water creates an incredible swirling effect.

Letterbox Lab Review Investigate Box

You also add a few iron filings and use a magnet (yep, there are magnets in this box) to move them around and create more swirls.

Letterbox Lab Review Investigate Box

OK, so here are the magnets!

Two bullet-shaped magnets which really do buzz when they snap together. Actually, the sound is more of a loud metallic rattle, but noisy things are fun, right?

They are impressively strong, and there’s even an experiment to make a paperclip float!

Letterbox Lab Review Investigate Box

Also included is a little pot of magnetic slime, which behaves like regular slime except that it is magnetic. It’s not strong enough to pick things up, but you can use the magnets to move it around, stretch it, and see what other effects you can come up with.

As well as using them in experiments, magnets are brilliant to play with. If you didn’t play with them as a child, feel free to catch up now.

Letterbox Lab Review Investigate Box

Letterbox Lab Review Investigate Box

Marble Mystery is both a puzzle and an experiment.

You have to get a marble from the top of a test tube full of sand to the bottom.

The booklet won’t tell you how, you have to figure it out yourself. As you can see, we did! And I’m not going to tell you how either, you’ll have to do it yourself. 

As well as the magnets, test tube, slime etc, there was a nice little bonus in this month’s box, a Dinosaur Excavation Kit. 

Letterbox Lab Review Investigate Box

You get a block of plaster containing a little dinosaur skeleton and plastic tools to dig it out. The plaster is soft enough to be removed by little hands, and it’s really fun seeing the bones emerge.

Letterbox Lab Review Investigate Box

OK, it’s not an actual dinosaur, but it looks very cute!

As this is the third box the the series of 12, there is one more thing.

Letterbox Lab Review Investigate Box

A certificate! Level 3 Bronze Investigator. 

All Letterbox Lab boxes are awesome, but this one is particularly fun. The magnets are a fantastic addition to our collection of scientific items, and Little C has been playing with them a lot. There is a great deal that is tactile this month, this combination of learning and fun has been particularly engaging.

Letterbox Lab is able to combine fun with learning in a very clever way. The little cartoon guides explain everything at children’s level without every being patronizing to talking down to them.

Children are encouraged to experiment and question, and the learning process is fascinating. This would be a superb supplement to home education as well, though they support and enhance regular school learning as well. 

Letterbox Lab is presented in a totally neutral way. Science and STEM subjects are for everyone, and this really reinforces that idea.

These boxes are a wonderful way to introduce your children to scientific principles and method, while playing with and producing some really cool things!


Thanks for reading! Pin this image, and take a look at other Letterbox Lab reviews here.

Take a look at some of the excellent magnetic and slime experiments in the third Letterbox Lab Investigate Box!

Letterbox Lab provide innovative children’s science kits as subscription boxes. We were sent this kit at no charge, and all opinions are our own.

The Explore Box (£8 + £2 postage) is for kids aged 6+ and contains a least an hour’s worth of fun science.

The Investigate Box (£22 + £2 postage) for kids aged 8+ has more experiments and more items of collectible lab equipment with enough to keep a junior scientist busy for 3 or 4 hours.

Both kits have full-colour illustrated instructions and online videos to make it easy to do all the experiments.