Rounding and estimating whole numbers explain what is it and what to do

Rounding numbers means you change the number to a closer, easier number. For example if you want to round 56 to the nearest tenth, it would round to 60.
Estimating numbers is when you guess numbers. For example, if you want to estimate the measure used to measure a bed, i would estimate feet.
I hope this helped:))

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)