These prompts can be done for more than just math symbols. 

Nano Banana Pro Prompt: 
A photograph of a massive, weathered stone ruin in a desert, shaped like the Chinese character for ‘WALL’ (城). A section of the Great Wall of China is integrated into the strokes of the character, with watchtowers and crumbling battlements. A caravan of camels and miniature figures treks along the base of the stone structure.