Name Class Date
Skills Worksheet
Math Skills – Chapter 29
Scientific Notation and the Sun
The sun has immense size and extreme temperatures compared with the Earth. The numbers used to describe the sun can be large and unwieldy, but by using scientific notation these numbers can be easier to read and write. Scientific notation expresses large numbers as a number between 1 and 10 multiplied by a power of 10. For example, scientific notation expresses 800,000 as 8 ´ 105.
A power of 10 is expressed as 10 with an exponent, or a number written above and to the right of another number. With powers of 10, the exponent tells how many zeros follow the number one. For example: 101 is 10 × 1, or 10 (one zero); 102 means 10 ´ 10, or 100 (two zeros); and 103 is the same as 10 ×10 ×10, or 1,000 (three zeros). To write a large number in scientific notation, identify the digits that are not place-holding zeros. Place a decimal to the right of the left-most digit. To find the exponent of 10, count the number of places to the right of the decimal point. For example, for 72,000, you would place a decimal to the right of 7 to get 7.2 (a number between 1 and 10). The exponent of 10 would be 4, or the number of places to the right of the decimal. In scientific notation, 72,000 equals 7.2 ×104.
SAMPLE PROBLEM:
An example of a large number used in describing the sun is the temperature of some solar flares: 20,000,000°C. Express 20,000,000°C in scientific notation.
SOLUTION
Step 1: Place a decimal to the right of the left-most digit.
2.0
Step 2: Count the number of places to the right of the decimal.
There are 7, so the exponent of 10 would be 7.
107 = 10 × 10 × 10 × 10 × 10 × 10 × 10 = 10,000,000
Step 3: Write 20,000,000 in scientific notation.
2 = 107 °C
Math Skills continued
PRACTICE
Using the sample problem as a guide, answer the following questions. Remember to show your work.
1. The temperature of the core of the sun is about 15,000,000°C. Use scientific notation to write the temperature of the sun’s core.
2. The speed of light is about 300,000 km. Express this number using scientific notation.
3. The sun’s diameter is about 1,390,000 km. Use scientific notation to express the diameter of the sun.
4. The sun converts more than 600 million tons of hydrogen to helium every second. Write 600 million tons using scientific notation.
5. Some gas jets that shoot out of the sun’s chromosphere reach 16,000 km in height. What is their height in scientific notation?
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Earth Science 24 The Sun
ANSWER KEY
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Earth Science 53 The Sun
ANSWER KEY
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Earth Science 53 The Sun