2. There are two-sevenths fewer trees related to squirrels than cypress trees, and (cypress) trees × two-sevenths = (cypress trees are more than squirrels); This year's output is one eighth higher than last year's, and (last year's) output × one eighth = (this year is higher than last year's) output.
3. 80× 2/5 of1class is 32, and 80×1/4 of class 2 is 20.
4.24× 1/4 = 6 liters of milk, 6× 6/5 = 7.2 grams of calcium.