More maths functions in level 5: no round ups and allow use of <>

[MarleenGilsing]

I think 2 maths functions could/should be added to level 5.

When using the math functions from level 5 and up Hedy will always round up the numbers.
I think it's great that Hedy is not that specific and doesn't give you endless decimals behind the comma. But I think it would be better if Hedy could use 2 decimals. This way students could write programs about money or anything with decimals really... Children know about decimals from a young age, so it shouldn't be an issue for them. If we want Hedy to still be able to round up, we could even make it into a new command?

The < and > are now introduced in a higher level, even though I think most students will already be familiar with these signs from maths class. I think these signs should be incorporated in level 5. Maybe the <= will be more difficult, so they could be allowed for students who want to use it and understand it, but they don't have to be in there if we think that'd be too much.

[MarleenGilsing]

@Felienne and I discussed this, which resulted in discussion #903