Range from High to Low

Lesson Plan - Get It!

Audio:

Range is the difference between the highest and lowest numbers in a group of numbers or set of data.

Remember that "difference" means to subtract.

1. First, put the numbers in order from least to greatest.
2. To find the range, subtract the highest value and the lowest value.

That's all there is to it! Except one thing — when analyzing data, it is important to remember that sometimes the range can be misleading if there are extremely high or low values in the set of data.

Take a look at some examples. Don't forget: the highest value is written first when subtracting.

Find the range of {4, 6, 5, 3, 10}.

1. First, arrange the numbers in order from least to greatest {3, 4, 5, 6, 10}.
2. Next, subtract the highest and lowest value in the set [10 - 3 = 7].

The range is 7.

Find the range of {-5, -1, 15, 4, -8}.

1. First, arrange the numbers in order from least to greatest {-8, -5, -1, 4, 15}.
2. Next, subtract the highest and lowest value in the set [15 - (-8) = 23].

In this problem, the 8 is negative. When we subtract a negative, it is the same as adding the positive number. If you imagine a number line, it is 8 units from -8 to zero, and then 15 units from zero to 15. The range would be 23 in this case.

Henry played a new game and recorded his scores. What is the range of his game scores?

89, 73, 56, 101, 91

1. First, arrange the numbers in order from least to greatest {56, 73, 89, 91, 101}.
2. Next, subtract the highest and lowest value in the set [101 - 56 = 45].

The range of his game scores is 45 points.

Discuss the following questions with your parent or teacher:

1. What is the range?
2. How is the range found?
3. What should you do with the numbers before you find the range?

Now that you know what "range" is, move on to the Got It? section to practice finding the range by playing "What a Deal!"