Back to Choose appropriate accuracy — Problem 5 · Task Set 6

Exercises: Choose a Level of Accuracy Appropriate to Limitations on Measurement When Reporting Quantities

Work through each section in order. Show your work where indicated. Remember: the goal is to report the right number of digits, not the most digits.

Grade 9·22 problems·~40 min·Common Core Math - HS Number and Quantity·standard·hsn-q-a-3

Work through problems with immediate feedback

Fluency Practice

A ruler is marked in millimeters. A student measures a piece of wood and reports its length as $23.427$ mm. What is the problem with this report?

No problem — more decimal places always improve accuracy.

The reported precision (0.001 mm) exceeds the ruler resolution (about 0.5 mm by estimation). The wood cannot be known to the nearest 0.001 mm from a millimeter ruler.

The measurement should use centimeters instead of millimeters.

The problem is that the measurement is too long — the wood must be shorter.