Description in the back of the box:
"Maantie [Highway] is an easily adopted dice game, where combining the spot counts and summation skills are the key to victory. Maantie is an excellent way to train mental arithmetics and thus has long been the dice game favourite of the young.
Abroad Maantie is known as Matterhorn, which is also played as a gambling game."
The idea of the game is to get all the numbers from 1 to 12 and back to 1, in order, by a single die or by combining multiple dice.
Maantie includes three dice, a scratch pad with scoring tracks, the rules and a pen.
To be precise, 'Maantie is NOT Matterhorn as the publisher claims. There is a slight difference in the rules. Instead, Maantie is better known as Centennial, Ohio or Martinetti.