Curated OER
Three-Digit Addition
Students work with hundreds place value, create and manipulate three-digit addition problems, and add three-digit numbers.
Curated OER
The Abacus
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.
Curated OER
"ty" number
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...