An abacus may be old, but it's still a great visual tool. Young mathemeticians look at, study and analyze 8 abacus images. They look at each image to determine how many beads are in each place value. They work with thousands, hundreds,...

Students work with hundreds place value, create and manipulate three-digit addition problems, and add three-digit numbers.

The class reads an explanation of the how the ancient calculation tool, the abacus, works. They examine four abacus images and record the number shown on each of them.

Second graders encounter the need to assess the code in English for tens is that the word ends in "-ty." They explore the meaning of two or three digit whole numbers to realize that the meaning of words like sixty can be decoded by...