Big Class - Fewer Hands On Activities

I was subbing in a fourth grade class the other day.  The teacher's homeroom class was 30 students, but all of the fourth grade teachers teach math at the same time and they switch around, based on ability, I assume.  The math class I had was 34 students.  The assignment was to cut out math "code" cards.  There were pieces for hundreds (100 through 900), tens, ones, tenths, hundredths, and thousandths.  I am not sure if there were also pieces for thousands.  But, even so, not only is that a lot of cutting, it is a huge task to keep track of all those pieces.  I eventually found enough baggies for each student to put his/her pieces in, but the cutting and bagging took WAY more time than was allotted for the lesson.  We didn't even begin using the pieces, because most of the students were still cutting - and losing pieces on the floor.  A few students forgot or didn't have the appropriate workbooks, quite a few students didn't have scissors. 

The lesson is actually an interesting one.  The cards overlap, so that to form the number 264.25, you would use the 200 piece, the 60 piece, the 4 piece, the 0.2 piece, and the 0.05 piece.  Then, to change to expanded form, you just expand the cards and you see right away:  200 + 60 + 4 + 0.2 + 0.05.  But doing this with 34 students is a challenge.

One of the other (regular) teachers asked me how the lesson went and I was explaining to her that I had a hard time getting through even the cutting out part, because of all of the logistical difficulties.  She teaches one of the lower ability classes and has a slightly smaller group, but she says that she doesn't do those activities, because they are way too much hassle for their worth. 

I have subbed in a LOT of elementary classes and I am finding this to be almost universally true.  The beautiful, well-thought out manipulatives collect dust (or languish in unopened shrink wrap) and the hands-on lessons are simply skipped. It is a shame.  Kids often really like the manipulatives and, even though they are a lot of work, I think some kids really need them.  But using or making manipulatives with 34 nine and ten year olds is daunting. 

I wonder if there are Montessori materials that do the same lesson.  It would be nice to have more solid pieces than the flimsy paper ones.  But, of course, that would be horrendously expensive for such a class, even if two kids shared.