Question

Estimate the following sum by clustering. 128.2 + 129.11 + 132.5

Answer 1

If we round each of these numbers Then we get a good estimation 
128.2 rounds out to be 130 
129.11 rounds out to be 130
132.5 rounds out to be 130

So now we just add these rounded numbers up. 
130 + 130 + 130 = 390

So our answer is 390

when in doubt, eat a pineapple, trust me it helps. :)

Answer 2

Answer:

390

Step-by-step explanation:

Estimate the following sum by clustering.

Round the number to find the sum of the given numbers

128.2 can be rounded to whole number 128 because we have 2 after the decimal point that is less than 5

129.11 can be rounded to whole number 129 because we have 1 after the decimal point that is less than 5

132.5 can be rounded to whole number 135 because we have 5 after the decimal point that is equal to 5

$128+129+133=390$