You and I are going to play a game. We have one million grains of sand in a bag. We take it in turns to remove
Would you go first?
For every natural number
Show that
There are
There are two types of legal moves: 1. Add a new empty box labelled
Prove it is possible to go from an initial position with
We can define the absolute value
Prove that
Prove that
Two fractions sum up to
On her birthday, my grandma was asked how old she was. She said: "Start with the year I was born. Add the current year to it. Then, from the sum subtract the year I celebrated by
In the long addition above, each letter corresponds to a different digit. What is the sum
Let