Runes and Roman Numerals are fun to learn and use . If you think about roman numerals in sets of five they are easier to learn. Look and see if you can work out the pattern. Runes were kept simple and if you notice they are mostly lines. This is because in the 1st and 2nd century, travellers wanting to leave messages didn't have pen and pencil or mobile phone. All they had was their knife which was used for everything. It was much easier to carve a straight line into a post, a rock or a tree than try to carve a circle. This was the way they left news or messages to other travellers  Have fun and  then maybe you could invent your own secret language