Are you still looking for how to calculate the sum of first 15 multiples of 7? Take a look at this article, here will introduce a calculator and 2 methods, which allow you to quickly calculate the sum of first 15 multiples of 7.

# What is the sum of first 15 multiples of 7?

## 1. Sum of first 15 multiples calculator

This method is suitable for all people, especially those without professional knowledge. It is strongly recommended to use this method.

Just enter the multiple of 7 into the input box, and then click the calculation button. In the blink of an eye, the calculator will figure out **the sum of first 15 multiples of 7 is 840**.

In addition, you will get 3 useful information:

- The first number of first 15 multiples of 7 is 7.
- The last number of first 15 multiples of 7 is 105.
- The average of first 15 multiples of 7 is 56.

If the number you want to calculate is not the top 15, you can use our other calculator: Sum of First N Multiples Calculator.

## 2. Basic method

This is the most basic method. First, calculate the first 15 multiples of 7, and then add up the calculated values.

### List of first 15 multiples of 7

- 7 * 1 = 7
- 7 * 2 = 14
- 7 * 3 = 21
- 7 * 4 = 28
- 7 * 5 = 35
- 7 * 6 = 42
- 7 * 7 = 49
- 7 * 8 = 56
- 7 * 9 = 63
- 7 * 10 = 70
- 7 * 11 = 77
- 7 * 12 = 84
- 7 * 13 = 91
- 7 * 14 = 98
- 7 * 15 = 105

Add up these 15 numbers

7 + 14 + 21 + 28 + 35 + 42 + 49 + 56 + 63 + 70 + 77 + 84 + 91 + 98 + 105 = 840

It can be seen that the sum of first 15 multiples of 7 is 840, which is consistent with the result calculated by the first method.

## 3. Common divisor method

Since these 15 numbers are all multiples of 7, 7 is the common divisor of these 15 numbers. We can first extract the common divisor 7, and then calculate the sum of these 15 numbers which are divided by the common divisor 7. Finally, multiply the sum by 7 to get the sum of first 15 multiples of 7.

Because these numbers are first 15 multiples of 7, after extracting the common divisor 7, these 15 numbers are 1 to 15. Now, calculate the sum of 1 to 15.

1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 + 12 + 13 + 14 + 15 = 120

Next, multiply the sum by 7

120 * 7 = 840

The answer came out. The sum of first 15 multiples of 7 is 840, which is consistent with the first and second methods.

Alright, the three methods are introduced. Please leave a message to tell me which method is more suitable for you?

## Latest calculators

Sum of Cubes of First N Natural, Odd or Even Numbers Calculator

Sum and Difference of Two Cubes Calculator with Steps

Sum of First N Multiples Calculator

Sum-Squares-Based Consecutive Integers Calculator

Sum of Consecutive Squares Calculator With Steps

Sum of Three Consecutive Integers Calculator

Sum of Two Consecutive Integers Calculator

Consecutive Integers Calculator Based On A Given Product

## Latest solutions

What is the sum of first 7 multiples of 9?

What is the sum of first 8 multiples of 8?

What is the sum of first 10 multiples of 6?

What is the sum of first 100 multiples of 5?

What is the sum of first 15 multiples of 4?

What is the sum of first 8 multiples of 3?

What is the sum of first 10 multiples of 7?