Loop Puzzle· Advanced

Goal

Draw a single closed loop on the dot grid.

How to Play

  • Tap an edge between dots to draw a line.
  • Tap the same edge again to mark X (no line).
  • Tap once more to clear the mark.

Rule 1: Number Clue

A number in a cell tells you exactly how many edges around that cell are part of the loop.

2OK
2NG

Rule 2: Single Loop

All lines must form one continuous closed loop. No dead ends or branches allowed.

OK
NG

Completed Example

  • Numbers in cells indicate how many edges around that cell are part of the loop.
  • The loop cannot cross or branch. Each dot connects to 0 or 2 line segments.
  • Empty cells (no number) have no constraints.
32023111

Tip

  • Start with 0 and 3 clues — they determine the most edges.
  • Look for diagonal 3-3 patterns and corner number patterns.
  • Use X marks actively to quickly narrow down remaining lines.

Visuospatial reasoning training promotes prefrontal activation and enhances mathematical thinking in children.

  • Lin, Y. et al. (2021). Spatial cognition training in 17,000 children. Nature Scientific Reports.