100 chart would equal adding 20. The student says that it is 2 jumps of 10, which
highlights that jumping down 2 rows on the 100 chart is the same as jumping
down two 10s, which is the same as adding 20. He also asks a student to count by
1s to check that jumping down 2 rows really is 20. Some students may need to
count by 1s to really see that the amount is 20 and to connect the familiar count-
ing by 1s to perhaps an unfamiliar idea of counting by 10s.
Most of the video shows Michael working with two students, Amanda and
Michael, while the other students are working independently in pairs. As he
works with these two students, Michael asks questions about how they are mak-
ing their moves and makes decisions about what he asks them to do to assess what
they are understanding and not understanding. He uses some of the information
he gathers to immediately try to help the students move forward in their under-
standing. For example, Michael (the teacher) notices that Michael (the student)
is counting each space, but is doing it in groups of five. He asks Michael about
this and then begins to build on this strategy by asking him to mark off every fifth
square. Michael then seems to see the jumps of 5 he can make without counting
every space, though he later reverts back to counting each space.
Right after they talk through counting by 5s, the teacher asks Michael to do
another move (to start at 20 on the 100 chart and then add 20). By doing this,
he may want to find out whether Michael would make the same mistakes or
whether he would incorporate anything they just talked about. When Michael
gives three different answers for starting at 20 and adding 20, the teacher re-
sponds, “Show me” to each of Michael’s answers about where he would land when
he makes the move. This communicates that he wants Michael to prove his an-
swer no matter whether his answer is correct or not.
Because Michael is unsure of the answer, the teacher urges him to use the
strategy of counting groups of 5 that he used before. By doing this, he is en-
couraging Michael to use and build on a strategy that he already knows. He also
repeatedly asks Michael to show his answers by actually moving the game piece.
By doing this, he can see how Michael is coming up with his answers and it
helps Michael see the answer visually on the chart by actually moving the
piece.
He asks Michael explicitly to jump by 5s. He thinks this is a strong strategy
that uses what Michael already knows and he wants to see if Michael can use that
knowledge to carry out the counting by 5s strategy and move away from counting
by 1s. When Michael goes back to counting groups of 5 by 1s, the teacher asks
Amanda to jump by 5s, perhaps because he wants Michael to see how another stu-
dent can use that strategy.
When Amanda jumps backward by 5s instead of forward by 5s, the teacher
poses a story about pennies to help Amanda reflect on whether where she landed
Get to 100