A student adds two numbers together. How can the student determine the number of significant figures in the answer?

A student measures her height with a meter stick and finds that she is about 1.5 m tall. How can she measure her height with greater accuracy and precision?

Student measures the length, width, and height of a fish tank. She finds that the fish tank is 105 cm long, 75 cm wide, and 80.5 cm high. What is the volume of the fish tank? Show your work. Use scientific notation and show the correct number of significant figures in your answer.

Answers

Question 1

After adding the two numbers together, you will find a number. To determine the number of significant figures, count the digits from right to left. The zeros on the left end and the right end are not significant. The zeros between the non-zero digits are significant.

Question 2

A mete stick is shorter than the student. So by using it, she will be force to take the measurements twice then add then together to get her height. This increases the chances of making errors. To improve the accuracy she should change the measuring instrument and use a tape measure. This will allow her to make only one measurement.

Question 3

Volume = length * width * height

= 105 * 75 * 80.5

= 633,937.5 cm³

In scientific notation;

633,937.5 cm³ = 6.339375 * 10⁵ cm³