1 crab has 8 legs.

2 crabs with 16 legs.

3 crabs with 24 legs.

4 crabs with 32 legs.

The specific algorithm is as follows:

1*8=8

2*8=16

3*8=24

4*8=32

Extended information:

Nine-nine formula:

The nine-nine table generally only uses 9 numbers from one to nine. .

The multiplication formula is the basic calculation rule for multiplication, division, square root and other calculations in ancient Chinese calculations. It has been used for more than 2,000 years. The nine-nine table is also the basic skill of primary school arithmetic.

The shortest multiplication table in the ancient world. The Mayan multiplication table requires 190 items, the Babylonian multiplication table requires 1770 items, and the multiplication tables of Egypt, Greece, Rome, India and other countries require infinite items; the 99 table only needs 45/81 items.