Activity: The Pattern Machine

The machine has a secret rule. Figure it out by looking at what goes in and what comes out!

Machine #1

Rule: _________________________

IN (n)OUT
15
26
37
4?
10?

Machine #2

Rule: _________________________

IN (n)OUT
13
26
39
4?
10?

Machine #3

Rule: _________________________

IN (n)OUT
19
28
37
4?
10?

Challenge Machine

Rule: _________________________

IN (n)OUT
13
25
37
4?
10?