Do you want a quick way to assess if your students are mastering the concept of counting correctly ten blocks to make a number? If so, try the Explain Everything App. The first graders had to write a 2-digit number in the box. Then they had to drag the correct number of tens and ones blocks to the larger box. The students then had to use the pointer to practice counting the base ten blocks. Finally, the children were able to record their voice, counting correctly to the 2 digit number. The students then did the same activity with an addition problem with two 2 digit numbers with one being a multiple of ten. A teacher can easily see who is not able to switch the counting from tens to the ones. Following is an example of Owen demonstrating his ability to explain how to count correctly the base ten blocks that corresponds to the given number.