Course 2Chapter 4 Section 9

Precision

Precision:

Refers to the degree of exactness. The marks on a scale or other instrument tell you the precision that is possible.

Example 1: Finding PrecisionWhat is the greatest precision possible with each ruler?

14 inch

Count the lines between the whole numbers to find the precision.

Example 1: Finding PrecisionWhat is the greatest precision possible with each ruler?

18 inch

Count the lines between the whole numbers to find the precision.

Example 1: Finding PrecisionWhat is the greatest precision possible with each ruler?

12 inch

Count the lines between the whole numbers to find the precision.

Example 2: Precision inMeasurement

Choose the more precise measurement.

25.5 grams or 11 gramsSince the units are the same, we look at the decimal place. The number with the most decimal places is the most precise.

Example 2: Precision inMeasurement

Choose the more precise measurement.

16.9liters or 13.25 litersSince the units are the same, we look at the decimal place. The number with the most decimal places is the most precise.

Example 2: Precision inMeasurement

Choose the more precise measurement.

2 feet or 13 inchesSince the units are the different, we choose the smallest unit.

Example 3: Precision and Rounding

Find each sum or difference. Round your answer appropriately.

45 m – 0.9 mSince 45 m is less precise than 0.9 m, round to the nearest whole number. The difference is…

44 m

= 44.1 m

Example 3: Precision and Rounding

Find each sum or difference. Round your answer appropriately.

11.4 g + 2.65 gSince 11.4 g is less precise than 2.65 g, round to the nearest tenth. The sum is…

14.1 g

= 14.05 g

Example 3: Precision and Rounding

Find each sum or difference. Round your answer appropriately.

2 L + 1.75 LSince 2 L is less precise than 1.75 L, round to the nearest whole number. The sum is…

4 L

= 3.75 L