Explanation

The pattern of the series is obtained by dividing the previous term by 2:

• 2 ÷ 2 = 1
• 1 ÷ 1 = 1
• 1 ÷ 2 = 1/2
• 1/2 ÷ 2 = 1/4
• 1/4 ÷ 2 = 1/8

So, the next number in the series is 1/8.