Input/Output Machines

Today we learned about how Input/Output Machines work. In grade 6, we learn about patterns with 2 steps. Click the video below to see what we did in class today briefly.

We also learned that we can work backwards to figure out what the operations are in the machine by looking at the pattern of the output. In the video above, if we look at the output numbers, we can see that they go up by 3 each time. This gives us a hint that the first operation is to multiply by 3. So we try it out! 1 x 3 = 3 .....not 4! So this tells us that we have to add one more. Let's try that throughout the table:

1 x 3 = 3, 3 +1 = 4 check
2 x 3 = 6, 6 + 1 = 7 check
3 x 3 = 9, 9 + 1 = 10 check.

So we can say that the first operation is to multiply by three, then add 1. Here is a link to an interactive website that will let you practice:

Function Machine