# Accuracy and Precision Worksheets

What is Measurement Accuracy? Mathematics is all about accuracy. But have you ever wondered what exactly accuracy means? It is the state of being correct, exact, or just right. However, the definition changes a little bit when it is defined in technical terms. In technical terms, the definition of accuracy is; 'The extent to which the value of a calculation, amount or a measurement comply with the correct value or a standard.' When we talk about numbers, accuracy plays a pivotal role because it defines the precision of a measurement. This term is known as 'Measurement Accuracy.' To better understand what measurement accuracy is, let's elaborate this term a bit more. It is the comparison of measurement against a set standard in order to determine whether or not the calculated measurement is correct or reliable. Measurement accuracy is recognized as the alteration/variation or difference between the factor measurements and the accepted value of the factor which is derived or calculated from a trusted external source. It can also be the percentage by which the two values vary or differ.

### Aligned Standard: HSN-Q.A.3

- Precision Step-by-step Lesson- Which measurement is the most precise?
- Guided Lesson - What is precision and what is the maximum level of acceptable error on your watch and a shape?
- Guided Lesson Explanation - This walk through should put you more at ease.
- Practice Worksheet - The practice sheet really helps hammer these skills home.
- Matching Worksheet - Visual accuracy and precision. Which object has the most or least.
- Error in Measurement Worksheet Five Pack - This should give you plenty of practice across the board.

- Answer Keys - These are for all the unlocked materials above.

### Homework Sheets

The word problem consist of two to four sentences here to work on reading in the content area.

- Homework 1 - We can identify b as being the most precise, because the distance has been measured to the most decimal places.
- Homework 2 - The measurement of 66 minutes was made to the nearest whole minute. The greatest possible error is half of 1 minute, which is 0.5 minutes.
- Homework 3 - First, we have to find out the greatest possible area. We should measure each to the nearest whole meter, so the greatest possible error is half of 1meter, which is 0.5 meters.

### Practice Worksheets

These problems are less wordy, if you will.

- Practice 1 - Write the greatest possible error for a measurement of 76 minutes?
- Practice 2 - Write the minimum and maximum possible area you can calculate, by taking measurement error of the square which is given below with its dimensions.
- Practice 3 - We should know that precision is the number of significant digits to which a value has been reliably measured.

### Math Skill Quizzes

Some of the quiz problems have two parts. Make sure to point that out.

- Quiz 1 - Which one has low accuracy and low Precision?
- Quiz 2 - Write the minimum possible area you can calculate, by taking measurement error of the square which is given below with its dimensions.
- Quiz 3 - We know that the greatest possible error is half of the unit of measure to which a measurement is rounded.

### What's the Difference?

While many people feel that these terms are indistinguishable, they are far from that. Accuracy is a based only on a single factor and how close the measure is to the absolutely true value. Precision on the other hand takes into account several measures to understand how close something is to being exact. A good way to understand the difference is to think about how a baseball player throws to same exact spot. Imagine that a catcher would just leave his glove at the same location, hoping pitcher puts it in the exact spot. If the pitcher is accurate, he will pitch the ball very close or in the glove every time. If he were to pitch with precision the ball will hit the same spot every single time, but that may not be dead center of the catcher's glove.

### Is Accuracy or Precision More Important?

When it comes to any form of measure, we want reading to be correct. This can be gauged by these two terms. Both of these terms are used almost synonymously in language. Accuracy is used to gauge the correctness of a series of measures to a standard of some kind. The standard is often achieved through hundreds, if not thousands of groups of operators with various types of equipment. The mean of all those measures creates a foundational standard. Precision reflects how close a series of measures are, but they do not reflect a standard. With precision we want our measures to be both repeatable by the same operator and equipment and reproducible by other operators and similar equipment. The end answer to the initial question is that it is depend on the situation you are exploring. If you are working in an environment that many different groups have already explored, accuracy is your goal. If investigating something entirely new, precision is your goal with your measures.