Then I got wise, had everyone move to the carpet, and we pulled out the unifix cubes.
Start out by building the base number-26. The first thing we were asked to do was add one more. Students had to specify that we were not adding another 'long' of 10 cubes, but just one single cube.
When we add one more cube and recount the total, we see that we have 27. To do the next one, we have to take away the extra cube first so we are back at the original number.
Now on to the 10s. Once again, we started with the base number- 26. Then my students had to explain why we were adding a 'long' instead of just a 'cube'.
Student- Mrs. Delk, we have to use a long because it has ten. A cube is just one.
Go back to the base number and try 10 less.
I know this might not seem like the hardest lesson, but believe me when I say my students were stumped for a good long while! I can tell we are going to have to have plenty of practice!
** Practice for home- I know you might not have unifix cubes at home ( I know I sure don't!) so try using dimes and pennies. Students can work on making money totals as well as adding and subtracting 10s and 1s.**