Nolan used the following procedure to find an estimate for StartRoot 18 EndRoot.

Step 1: Since 4 squared = 16 and 5 squared = 25 and 16 < 18 < 25, StartRoot 18 EndRoot is between 4 and 5.

Step 2: Since 18 is closer to 16, square the tenths closer to 4.

4.1 squared = 16.81

4.2 squared = 17.64

4.3 squared = 18.49

4.4 squared = 19.36

Step 3: Since 18.49 rounds to 18, 4.3 is the best approximation for StartRoot 18 EndRoot.

In which step, if any, did Nolan make an error?

In step 1, StartRoot 18 EndRoot is between 4 and 5 becauseStartRoot 18 EndRoot almost-equals 20 and 4 times 5 = 20.

In step 2, he made a calculation error when squaring.

In step 3, he should have determined which square is closest to 18.

Nolan did not make an error.

Question

Lilibeth

Mathematics

11 March, 10:28

Nolan used the following procedure to find an estimate for StartRoot 18 EndRoot.

Step 1: Since 4 squared = 16 and 5 squared = 25 and 16 < 18 < 25, StartRoot 18 EndRoot is between 4 and 5.

Step 2: Since 18 is closer to 16, square the tenths closer to 4.

4.1 squared = 16.81

4.2 squared = 17.64

4.3 squared = 18.49

4.4 squared = 19.36

Step 3: Since 18.49 rounds to 18, 4.3 is the best approximation for StartRoot 18 EndRoot.

In which step, if any, did Nolan make an error?

In step 1, StartRoot 18 EndRoot is between 4 and 5 becauseStartRoot 18 EndRoot almost-equals 20 and 4 times 5 = 20.

In step 2, he made a calculation error when squaring.

In step 3, he should have determined which square is closest to 18.

Nolan did not make an error.

+3

Answers (2)

Know the Answer?

Kaylee Hutchinson · Answer 1

In step 3, he should have determined which square is closest to 18.

Raegan Cortez · Answer 2

Nolan correctly identified the square numbers before and after 18.

The square roots of them are 4 and 5.

Clearly, square root of 18 should lie between 4 and 5 only.

He, then carefully squared 4.1, 4.2, 4.3 etc. and identified that 4.3 squared is nearer to 18.

Since, Nolan is finding estimated square root, his steps are cool and he didn't make any error.