Series and summation

What you'll learn

1. 1

   Imagine stacking coins — 1 coin, then 2, then 3, right up to 10. The total number of coins is a series, and adding them up is called summation.

2. 2

   Build the series 1 + 2 + 3 + 4 by stacking coins in rows.

3. 3

   Let's sum 1 + 2 + 3 + … + 10 using a clever trick.

4. 4

   How many pairs do you get when summing 1 to 20?

5. 5

   Use the number line to sum 2 + 4 + 6 + 8 (the first 4 even numbers).

6. 6

   Sum the series: 5 + 10 + 15 + 20 (multiples of 5).

7. 7

   What is the sum of the first 5 odd numbers: 1 + 3 + 5 + 7 + 9?