You can use integer counters to model
2
–
9
.Start with 2 positive counters.
Then take away 9 positive counters. You'll need to first add zero pairs until you have 9 positive counters to take away.
Subtract.
2
–
9
=
ref_doc_title.
Jumping to level 1 of 1
Excellent!
Now entering the Challenge Zone—are you ready?
