dice, bones
骰 centers on dice, the small cubes used in games of chance, and by extension the bones they were historically made from.
骰 combines 骨 (bone) with 殳, which likely contributes the sound. The character originally referred to dice made from bone.
The left side is bone 骨, and the right side looks like a hand holding a tool. Imagine carving dice from bone: 骰 is dice made of bone.
For トウ, picture throwing dice into a toe-shaped cup: toe -> トウ, and the dice rattle inside.
dice (esp. in mahjong); die