Teachers can make manipulatives that are reasonably accurate and inexpensive, but it takes time. Some suggestions are in the sections that follow. Making manipulatives with students is a good experience, but the results are sometimes not accurate enough for precise comparisons. As a process, it is social, provideslots of time for understanding, and provides lots of repetition with a purpose. It means that every student has a set, and knows how to make more for children and family.
Student activities using these manipulatives start on page 52.
These blocks are easier to use and put away if you buy a big plastic bin to hold them, and a small plastic box to hold the little ones. They come with a couple of sheets of activities for exploring the set.
Extend the set: If you have these blocks, it is interesting to work with students to extend the set so you can show very large numbers. A stack of ten 1000 cubes will give you an idea of the size and shape of 10 000. For each 10 000 rod, you will need a carton about 10 cm by 10 cm by 1 m; 10 of these will make a 100 000 flat. For this flat, 100 000, you will need a carton about 10 cm by 1 metre by 1 metre (the shape of large, square floor fan). 10 of these piled up will show 1 000 000. A million cube needs a carton about 1 metre by 1 metre by 1 metre. You will probably have to go outside to pile up 10 million, unless you have a high-ceilinged foyer somewhere.
Make your own: Getting students involved in making their own manipulatives is easy to do. For example, use toothpicks for a value of 1, put an elastic around 10 toothpicks to show 10, put 10 of these bundles in a baggie to show 100, and 10 baggies in a big envelope to show 1000, 10 envelopes in a bulldog clip to show 10 000. When your students get tired of bundling toothpicks to fill the baggies, they will begin to use empty baggies as symbols of 100. That's the day you can celebrate their understanding and their increasing comfort with the abstract!