Drag across adjacent cells to trace paths that evaluate to today's number. Cover every cell exactly once. No timer, no wrong-answer penalty.
A path is a finger-drag through connected cells (up, down, left, right). Each path is exactly one operation: two numbers joined by + or ×.
Numbers can be 1, 2, or 3 digits — consecutive digit cells form one multi-digit number in trace order.
Every path reads as one equation from one end to the other. It doesn't matter which end you began tracing from — the reading is always the same.
The reading starts at the path's leftmost end. If both ends are in the same column, it starts at the topmost one. The reading ends at the other end.
The tracer will refuse a path that extends further to the left than its own starting end — that would put the "leftmost" cell in the middle of the path, where the reading would get confused. Otherwise you're free to shape paths however you want: vertical runs, L-shapes, U-shapes, zig-zags.
The same 5-cell path traced two ways. The equation reads the same either time — left-to-right from the top-left.
When a valid path lights up green and you lift your finger, it commits. Those cells are locked. Keep going until every cell is part of a path.
Only + and ×. Evaluation is just one operation per path, so no precedence ambiguity ever comes up.