### 1-5: TEKS Practice

• 1. Express the number 80,000 in scientific notation.

• 2. Express the number 60,000 in scientific notation.

• 3. Think About the Process You want to express 437,000 in scientific notation.

• a. What is the first step?

• A. Move the decimal point 5 places to the left to get 4.37.

• B. Move the decimal point 4 places to the left to get 4.37.

• C. Move the decimal point 4 places to the left to get 43.7.

• D. Move the decimal point 5 places to the left to get 43.7.

• b. What is the result?

• 4. Express the number 8.5 × 105 in standard form.

• 5. The diameter of a certain star is about 9.3 × 106 km. Express this diameter in standard form.

• 6. Express 0.006 in scientific notation by counting decimal places.

• 7. Mental Math Express this number in scientific notation.

0.000000003

• 8.

• a. Writing Express the number 5.2 × 106 in standard form.

• b. Describe two advantages that scientific notation has over standard form. Describe two advantages of standard form. Give examples for each.

• 9.

• a. Writing Express 0.00000843 in scientific notation.

• b. How can negative powers of 10 make small numbers easier to write and compare?

• 10. Write 0.0000000485 in scientific notation by counting decimal places.

• 11. Error Analysis Owen incorrectly claims that because 20,000 = 20 × 1,000, he can express 20,000 in scientific notation as 20 × 103.

• a. What was Owen's error?

• A. The product he found is correct, but 20 × 103 is not in scientific notation since 20 is not less than 10.

• B. The product he found is correct, but 20 × 103 is not in scientific notation since 20 is not less than 1.

• C. He found the power of 10 incorrectly since 1,000 ≠ 103.

• D. He found the product incorrectly since 20,000 ≠ 20 × 1,000.

• b. Express 20,000 in scientific notation correctly.

• 12. Population A historian predicts that by 2050, about 1.56 × 107 people will live in a certain country. Express this prediction in standard form.

• 13.

• a. Express the number 586,400,000 in scientific notation.

• b. Describe a situation in which this number might arise. Explain why it would be easier to use scientific notation in that situation.

• 14. A nanometer is one-billionth of a meter. A centimeter is one-hundredth of a meter, and a kilometer is 1,000 meters. An X-ray can have a wavelength of 0.000000037 meter.

• a. Express this wavelength in scientific notation.

• b. Which unit is most appropriate for measuring the wavelength of an X-ray? Explain your reasoning.

• A. nanometer

• B. centimeter

• C. kilometer

• D. meter

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