Scientific Notation Exam

In the expanded form of 5.97 x 10 ²³  , how many zeros would trail 7 until the ones digit?

• 23

• 22

• 21

• 20

Answer explanation

In the expanded form of 5.97 x 10²³, the number of zeros trailing 7 until the ones digit is 21, which corresponds to the exponent in scientific notation.

What is ( 4.5 x 10⁴ ) - ( 6.8 x 10³ ) ?

• 3.82 x 10⁴

• -2.3 x 10⁴

• 3.82 x 10³

• -2.3 x 10³

Answer explanation

To subtract (4.5 x 10^4) - (6.8 x 10^3), first convert both numbers to the same power of 10. This gives us (45 x 10^3) - (6.8 x 10^3) = 38.2 x 10^3 = 3.82 x 10^4. Therefore, the correct answer is 3.82 x 10^4.

What is 0.0003780 in scientific notation ?

• 3.78 x 10⁴

• 3.78 x 10^-4

• 3.78 x 10⁵

• 3.78 x 10^-5

Answer explanation

To write 0.0003780 in scientific notation, move the decimal point to the right until there is only one non-zero digit to the left. This gives 3.78 x 10^-4, making the correct choice 3.78 x 10^-4.

What is 10.21 𝑥 10³ in standard form?

• 10.210

• 1021000

• 10210.00

• 0.01021

Answer explanation

To write 10.21 x 10³ in standard form, move the decimal point 3 places to the right, resulting in 10210.00.

What is (10.21 𝑥 10³)+( 2.05 𝑥 10²) in standard form?

• 10415

• 1041500

• 0.00145

• 1041.5

Answer explanation

To add numbers in standard form, ensure the exponents are the same. Convert 2.05 x 10² to 205 x 10¹. Then add: 10.21 x 10³ + 205 x 10¹ = 10415 in standard form.

(6 x 10 ³  ) x (3 x 10 ⁵  ) = ___

• 1.8 x 10⁸

• 1.8 x 10⁹

• 1.2 x 10⁸

• 1.2 x 10⁹

Answer explanation

(6 x 10^3) x (3 x 10^5) = 6 x 3 x 10^(3+5) = 18 x 10^8 = 1.8 x 10^9. Therefore, the correct answer is 1.8 x 10^9.

What is (7.89 x 10⁴) + (3.45 x 10³) in standard form?

• 82350

• 8235

• 823500

• 82350.0

Answer explanation

To add numbers in scientific notation, ensure the exponents are the same. Then add the coefficients. (7.89 x 10^4) + (3.45 x 10^3) = 78,900 + 3,450 = 82,350. Therefore, the answer in standard form is 82,350.

Express 0.00000067 in scientific notation.

• 6.7 x 10^-7

• 6.7 x 10⁷

• 6.7 x 10^-6

• 6.7 x 10⁶

Answer explanation

To express 0.00000067 in scientific notation, move the decimal point to the right until there is only one non-zero digit to the left. This gives 6.7 x 10^-7, which is the correct choice.

Calculate (2.3 x 10⁶) / (5 x 10²).

• 4.6 x 10⁴

• 4.6 x 10⁸

• 4.6 x 10³

• 4.6 x 10²

Answer explanation

To divide numbers in scientific notation, divide the coefficients and subtract the exponents. (2.3 / 5) x 10^(6-2) = 0.46 x 10^4 = 4.6 x 10^4. Therefore, the correct answer is 4.6 x 10^4.

What is (3.2 x 10⁷) + (4.5 x 10⁶) in standard form?

• 3.65 x 10¹³

• 3.65 x 10⁸

• 3.65 x 10⁷

• 3.65 x 10⁶

Answer explanation

To add numbers in scientific notation, ensure the exponents are the same. Add the coefficients: (3.2 + 0.45) x 10^7 = 3.65 x 10^7. Therefore, the sum is 3.65 x 10^7.