Cells multiply by means of cell division.
So we'll multiply by 1000 milliliters per liter.
To reduce pounds to pence you multiply by a hundred.
To convert Fahrenheit degrees into Centigrade, subtract 32o, and multiply by 5/9.
And in the even case, I'd square, divide by half, call this again: in the odd case, I go b minus 1 and then multiply by a.
When the factor to be cancelled is a base vector we dot-multiply by another base vector to produce a kronecker delta.
One trick, the scientists say, is to count what's in your cart and multiply by a guesstimate of the average cost of the items.
