no actually
15.75
9 + 63 = 72 lbs.
the purpose of rounding numbers is that you can get closer to the actual answer
rounding whole numbers and decimals
rounding numbers is to nearest ten or hundred and compatible numbers are when you can do nearest 5
Rounding is going to the nearest tens, hundreds, thousands etc., depending on the problem. Compatible numbers are numbers the work well with each other. Both of these are estimating.
50.0000.000
Not necessarily. Take this example: 89 ÷ 44 The rounding rules are clear. 89 goes to 90, 44 goes to 40, 90 ÷ 40 = 2.25 Compatible numbers can be altered by the relationships between them. 89 is close to 90, 44 is close to 45, 90 and 45 have a relationship that is easy to compute. 90 ÷ 45 = 2 In this case, the estimate provided by compatible numbers is closer to the real total than the one provided by rounding.
If I were multiplying I would like to round to tens so I can "annex" the zeroes. If I were adding I would like numbers that would equal 0 like 3+7 or 5+5 or 2+8. They are compatible numbers.
Compatible numbers would be easier. Rounding gives you 14 x 47. Compatible numbers could be 13 x 50 which would be closer to the actual product.
no actually
Not in this case.
15.75
Rounding the weights to 10 lb and 60 lb gives an estimated total weight of 70 lb. Using compatible numbers by rounding to 9 lb and 60 lb, the estimated total weight is 69 lb. The estimate using compatible numbers (69 lb) is closer to the actual total weight of 71.6 lb.
9 + 63 = 72 lbs.
Rounding is closer because the amount added to one number is the same as the amount subtracted from the other number which makes the answer match exactly.