Adding and Subtracting Numbers in Scientific Notation

What must be true about the exponents when adding or subtracting numbers in scientific notation?

• One must be zero.

• They must be negative.

• They must be the same.

• They must be different.

If you add 9.73 × 10^6 and 8.8 × 10^6, what is the result before adjusting to proper scientific notation?

• 18.53 × 10^6

• 1.853 × 10^7

• 18.53 × 10^7

• 1.853 × 10^6

How do you adjust 18.53 × 10^6 to proper scientific notation?

• Move the decimal one place to the right and subtract 1 from the exponent.

• Move the decimal one place to the left and add 1 to the exponent.

• Move the decimal two places to the right and subtract 2 from the exponent.

• Move the decimal two places to the left and add 2 to the exponent.

What is the result of subtracting 8.8 × 10^6 from 9.73 × 10^6 before adjusting to proper scientific notation?

• 0.61 × 10^6

• 6.1 × 10^2

• 0.61 × 10^3

• 6.1 × 10^3

How do you adjust 0.61 × 10^3 to proper scientific notation?

• Move the decimal two places to the left and add 2 to the exponent.

• Move the decimal one place to the right and subtract 1 from the exponent.

• Move the decimal one place to the left and add 1 to the exponent.

• Move the decimal two places to the right and subtract 2 from the exponent.

When adding numbers with different exponents, which exponent should you change?

• Neither exponent

• Both exponents

• The smaller exponent

• The larger exponent

If you have 4.7 × 10^7 and 3.4 × 10^6, how do you adjust the second number to match the exponent of the first?

• Move the decimal one place to the right and subtract 1 from the exponent.

• Move the decimal two places to the right and subtract 2 from the exponent.

• Move the decimal one place to the left and add 1 to the exponent.

• Move the decimal two places to the left and add 2 to the exponent.

What is the result of adding 4.7 × 10^7 and 0.34 × 10^7?

• 5.04 × 10^7

• 5.05 × 10^7

• 5.06 × 10^7

• 5.07 × 10^7

How do you adjust -6 × 10^-6 to match -5 × 10^-5?

• Move the decimal one place to the right and subtract 1 from the exponent.

• Move the decimal one place to the left and add 1 to the exponent.

• Move the decimal two places to the left and add 2 to the exponent.

• Move the decimal two places to the right and subtract 2 from the exponent.

What is the result of adding 2.8 × 10^-5 and 0.54 × 10^-5?

• 3.34 × 10^-5

• 3.32 × 10^-5

• 3.35 × 10^-5

• 3.33 × 10^-5