In this activity, you need to work out what goes in or what comes out of a Subtract Ten Machine.
16 - 10 = 6, so when 16 goes in, 6 comes out.
Also 6 + 10 = 16, so when 6 comes out, 16 must have gone in.
Let's try another one:
If I put 13 into the machine, what number will come out?
13 - 10 = 3, so the number 3 will come out!
How about if the number 4 comes out of the machine. What number must have gone in?
4 + 10 = 14, so the number 14 must have gone in.
Does this make sense? Shall we move on to try some questions?