McGraw Hill Glencoe Algebra 1, 2012
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McGraw Hill Glencoe Algebra 1, 2012 View details
2. Real Numbers
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Exercise 15 Page p10

You can approximate the value of a square root by comparing it to nearby perfect squares.

Solution: {2 14, 2.3, sqrt(7), sqrt(8) }
Graph:

Let's approach ordering the given set from least to greatest one number at a time.

First Value

First, we have 2 14. To graph this value, we find 2 on the number line and move 14 steps in the positive direction.

Second Value

We could type sqrt(7) into a calculator to help us graph it. Or, we can compare it to the square root of two nearby perfect squares. We will show how to do this second option.
4<7<9
sqrt(4)
2

Now, we know that sqrt(7) lies between 2 and 3 on a number line. We also know that 7 is 3 steps to the right of 4 and 2 steps to the left of 9 on a number line. 4+3 →7+2 →9 Therefore, 7 is closer to 9 than it is to 4. With that in mind, we can approximate the location of sqrt(7).

Third Value

Next, let's plot 2.3. This number can be rewritten as the mixed number 2 13 to help us visualize how to graph it. We find 2 on the number line and move 13 steps in the positive direction.

Fourth Value

Similarly, we could type sqrt(8) into a calculator to help us graph it. Or, we can compare it to the square root of two nearby perfect squares.
4<8<9
sqrt(4)
2
Now, we know that sqrt(8) lies between 2 and 3 on a number line. We also know that 8 is 4 steps to the right of 4 and 1 step to the left of 9 on a number line. 4+4 →8+1 →9 Therefore, 8 is closer to 9 than it is to 4. With that in mind, we can approximate the location of sqrt(8).

Combining the Number Lines

Finally, let's combine all of our number lines into one.

Now, we can write the set in order from least to greatest. {2 14, 2.3, sqrt(7), sqrt(8) }