Question 1
A square sheet of $9 \times 9$ is ruled into $1 \times 1$ unit squares. The sheet is cut with the goal of dividing it into the $1 \times 1$ unit squares.
Each cut must be straight and follow a line of the grid.
After each cut, it is allowed to rearrange the pieces conveniently into a stack so that the next cut divides several pieces simultaneously (in each piece the cut must be straight and follow a line of the grid). Folding the paper is forbidden.
What is the least number of cuts needed to achieve the goal?
(For the number found, indicate which cuts are made and explain why it is impossible to achieve the goal with fewer cuts.)
Each cut must be straight and follow a line of the grid.
After each cut, it is allowed to rearrange the pieces conveniently into a stack so that the next cut divides several pieces simultaneously (in each piece the cut must be straight and follow a line of the grid). Folding the paper is forbidden.
What is the least number of cuts needed to achieve the goal?
(For the number found, indicate which cuts are made and explain why it is impossible to achieve the goal with fewer cuts.)