If you were rounding to 90 from 80 you would going by the tens place. In this case in order to jump to 90 the value of 80s one place would need to be 5 or higher.
90
80
80
87.01 rounded to the tens is 90.
80 assuming it is rounded to nearest ten (as question does not say) 82 is 2 away from 80 82 is 8 away from 90 2 is smaller than 8 so answer is 80
80
90 * 80 = 7,200
80% of 90m = 80% * 90 = 0.8 * 90 = 72m
79.6 rounded to the nearest tens is 80. Then, 80 rounded to the nearest ones is 80.
80% of 90 Euros= 80% * 90 Euros= 0.8 * 90 Euros= 72 Euros
10
90 - 80 = 10