In these lessons, we will look at some examples of adding and subtracting numbers in
scientific notation

(Scientific notation is called standard form in the UK.)

**Related Pages**

Converting Scientific Notation

Multiplying Scientific Notation

Dividing Scientific Notation

The following diagram shows how to add or subtract numbers in scientific notation. Scroll down the page for more examples on adding and subtracting with scientific notation.

To add or subtract two numbers in scientific notation:

Step 1: Adjust the powers of 10 in the 2 numbers so that they have the same index. (Tip: It is easier to adjust the smaller index to equal the larger index).

Step 2: Add or subtract the numbers.

Step 3: Give the answer in scientific notation.

**Example:**

Evaluate 2 × 10^{3} + 3.6 × 10^{4}, giving your answer in
scientific notation.

**Solution:**

**Example:**

Evaluate 7 × 10^{5} – 5.2 × 10^{4}, giving your answer in
scientific notation.

**Solution:**

This video explains how to add and subtract numbers written in scientific notation, whether or not they have the same exponent.

**Examples:**

(3.769 × 10^{5}) + (4.21 × 10^{5})

(8.14 × 10^{-2}) - (2.01 × 10^{-2})

(7.58 × 10^{5}) + (2.871 × 10^{6})

(2.9785 × 10^{-8}) - (5.72 × 10^{-10})

(4.86 × 10^{3}) - (4.72 × 10^{3})

This video explains why when adding and subtracting numbers in scientific notation, you have to make sure the exponents are the same.

**Example:**

(7.1 × 10^{3}) + (5 × 10^{2})

This video reviews scientific notation and shows how to add and subtract in Scientific Notation.

Rule for scientific notation:

- If the exponent goes down, the decimal point goes right.
- If the decimal point goes right, the exponent goes down.
- If the exponent goes up, the decimal goes left.
- If the decimal point goes left, the exponent goes up.

This video explains how to do add and subtract in scientific notation without the use of a calculator.

- The powers of 10 must be the same in both terms in order to add/subtract.
- Once the power of 10 matches, just add or subtract.
- Adjust the answer to scientific notation.

Learn how to add and subtract in scientific notation.

Add and subtract numbers in different bases by rewriting their exponents to be the same.

**Example:**

(3.5 × 10^{4}) + (3.1 × 10^{5})

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