What is an aproximate estimate for 98.7 , 35.4 , 3.8 , 20.3

99 35, 4, and 20 if it is 5 and up round up. or if you want round up by tens it would be 100, 40, 1, 20

38+105= 143, 39+104=143, and you will find then adding the numbers on opposite sides, moving inwards yields the answer 138 every time. because of this, you’re going to multiply 138 times the number of pairs, which is 34. therefore, 34*138= 4692(i’m sorry if it’s the wrong numbers, but it’s the right concept)