What he's doing is representing numbers with their logarithms, with limited precision. A floating-point multiplier/divider, then, turns into a fairly small adde

What he's doing is representing numbers with their logarithms, with limited precision. A floating-point multiplier/divider, then, turns into a fairly small adder, which is much smaller and faster. Square roots and squaring turn into bit shifting. They have some clever method for doing addition/subtraction efficiently. And since they can fit all this in a small area with short critical paths, they can clock it very, very fast, and include a lot of them on a chip.