[Viliam1234]

Wow, the English translation sucks much more than I noticed. :(

The whole "stepping" thing is a reference to how they (in the web page author's country) teach basic addition and subtraction at first grade. There is a carpet with numbers on the floor, you start at number zero, and do addition like "2+3" means "two steps forward, pause, three steps forward, now look at the number you are standing on". The carpet is situated so that from the sitting kids' position the zero is on the left, and the numbers increase to the right.

The idea is to turn integers into something "tangible", in a way that can later be extended to negative numbers.

So the instructions should be like: "You start at given number. Right arrow means a step forward to a greater number. Left arrow means a step backward to a smaller number. What number you end at?"

Sorry, I already know all these things by heart, so I didn't notice how the English instructions don't make sense. Guess I should contact the author about it.