you have 17 marbles you have four more
than I do how many do I have you have 17
you have four more than I do how many do
I have
Turkey
yes Patrick salsa compares smaller
unknown problem by Counting or in fact
subitizing three times you have 17 you
have four more than I do
how many do I have he uses the
arithmetic rack to subitize 17
pushing over a ten and a seven at once
he then moves away for beads from the
seven and looks answering thirteen
yes Patrick makes use the structure of
the arithmetic rack to model 17 quickly
remove four and subitize the remaining
amount he is not following the structure
of the problem by matching two sets
instead he models it as removal of one
part from the whole to find the
remaining part we can infer his
deepening understanding of the part hole
relationship of addition and subtraction
in that he uses one set to model the
full problem
you