Find each sum or difference. round to the place value of the less precise measurement. 2.13 m + 8.6 m a. 6.47 m b. 10.73 m c. 11 m d. 10.7 m

The solution would be like this for this specific problem:

Given:

2.13 m

8.6 m

2.13 m + 8.6 m = 10.73 m

10.73 is the more precise measurement, while 10.7 is the less precise one so the answer is 10.7 m. Precise measurements are always better than imprecise ones, but more precise measurements are not always superior to less precise ones. 

The term precision means how precisely and object of study is measured and it also refers to the degree to which several measurements of the same object show the same or similar results. Measurement with high precision is very likely to produce the same and predictive results.

Were is the paralleloram? I don't see it. Can you attach a pic?