One compares a drink indicated on the left with another indicated at
the top and answers the question: How many times more, or how strongly more is that
drink consumed in the US than the one at the top? One then enters the number from the
scale that is appropriate for the judgement: for example enter 9 in the (coffee, wine)
position meaning that coffee consumption is 9 times wine consumption. It is automatic
that 1/9 is what one needs to use in the (wine, coffee) position. Note that water is
consumed more than coffee, so one enters 2 in the (water, coffee) position, and ½ in the
(coffee, water) position. One always enters the whole number in its appropriate position
and automatically enters its reciprocal in the transpose position.