From our calendar activities we know that the long block is worth 10 and the small block is worth one. We started by making numbers that Mrs. Betts gave us - we were very quick at this. We could make a number and tell how many tens and how many ones were in the number and how we record the number using numerals.
Then Mrs. Betts asked us to show how we could share the numbers we make between two people. It was easy to start with because she gave us numbers that had an even number of tens! It got a little harder when the number of 10s was odd. For example, how would you share 35 between 2 people?
Some one quickly realized that after sharing the two tens there was one ten left and 10 can be shared between 2 people - each person gets 5! Someone else said, "I know! We can make a trade - trade the one ten for ten ones!!!" What thinkers!
While we were learning to share numbers we developed a frame to help us share our thinking out loud. Here it is. . .
First we share the tens, then we share the ones. We count the number each person gets. If each person got the same number, the number is even. If each person got a different number the number is odd. We know that odd numbers can not be shared equally but even numbers can!
We practiced this many times so we became comfortable sharing our thinking.
The next day, Mrs. Betts gave us a challenge. She asked us to work with a partner and choose 7 numbers between 11 and 100. We had to make the number, share it and then record whether the number was odd or even.
After working through this challenge we met at the carpet to record our numbers and analyze our work. We looked to see if there was a pattern to the numbers. There was!!!! We found out that all odd numbers end in the numbers 1, 3, 5, 7 or 9 and all even numbers end in 0, 2 ,4, 6, or 8.
Using this information can you tell whether the number 368 is odd or even? How many would each person get if you shared it between two people?