My passion is Friction Fire, but I thought I would mention the Fire Steel (aka Ferro rod, see left photo.) Not to be confused with the traditional Flint and Steel (see right) where the steel would be struck against flint to create a spark. The Ferro rod is made from Ferrocerium which is a man-made metallic material invented in the 20th Century, which is struck against steel. The traditional Flint and Steel was the prevailing method of lighting fires from the Iron Age until the mid to late 19th Century and even in the early 20th Century; before matches and then lighters became prevalent. Before the advent of steel, a variety of iron pyrite or marcasite was used with flint and other stones to produce a spark.
I don't really like the Ferro rod as it is a modern invention and the hot sparks are actually very very hot metal shards. The Ferro rod is a very common bushcraft tool and can be an easy way to teach fire lighting before moving onto Friction Fire. Kid's do like Ferro rods due to the sparks but as always with kids and fire you need to teach them to be safe as Ferro rod sparks can hurt and cause things to catch fire! The sparks are actually shards of metal.
The Ferro rod is a modern take on the flint and steel, and consists of a Ferrocerium rod which is a man-made metallic material that produces hot sparks at temperatures of about 3,000 °C (5,430 °F) when scraped against a piece of steel. A fire steel usually comes with a metal striker but you can use the back of a knife as well - do not use the knife blade as it will damage and chip it. Ferrocerium is used in many applications such as cigarette lighters.
I don't really encourage use of Ferro Rods but they are fairly easy to use. You need to hold the rod firm, and point the rod towards the tinder , angle the striker about 30-45 degrees on the rod and push it down the rod applying pressure , and direct the sparks onto tinder It can be a very quick way and very useful in survival situations.
You need to strike the sparks onto the underside not the smooth outside of the ball. It only takes a small spark (or ember) to light. You will know when it is lit, as you will see a small red glow. Blow on it and the ember will get larger and it will burn like a coal. You can then place your dry tinder on top, such as dry clematis bark or dead dry grass or bracken. Blow onto the glowing ember, and keep blowing, it will start to smoke and may produce lots of smoke! Keep bowing until the tinder bursts into flame then place your kindling on top.
Please do use common sense when introducing children to fire lighting and teach them about fire safety, and always ensure they are supervised when fire lighting and around fires. It is a good idea to have a safe zone around a fire, marked out with sticks. Also, the sparks produced from a Ferro Rod are very HOT metal shards and can burn skin and catch things alight (e.g. tents) so children should be supervised when using them.