For most of the second part of this school year, the youngest children have been working on two digit place value. We started off counting up from the bottom of our board and looked at the numbers from 0-9. Of course they were all familiar with those numbers. Then, we added 10 on top of the list and stopped to talk about what was different between that number and all the rest in the list. As we added 2 digit numbers up to 20 we looked at what stayed the same and what changed and then went up to 30 looking for patterns.

 After that we began using 2 digit place value board with ones and tens blocks to make numbers. We picked two cards.  The first number was for the ones place and the second for the tens place. We did this with tens and ones bead sticks, dimes and pennies.

We switched to dimes and pennies and picture cards of items they could buy…putting dimes and pennies on the place value board and finding out how much the items cost. We played Guess My Number using a 100’s chart. We played MANY games including O NO! 99, 5 Tower- a game which plays to 50 by collecting 5 towers of 10, modified Black Jack, 2 Digit War and The Money Game.

We found out that students could read and order 2D numbers but when asked which number was in the ones place and which in the tens place they were more puzzled. We moved into playing with a 100’s chart with movable numbers. Students picked five numbers, ordered them, wrote them and then returned the 5 two digit tiles belonging to their neighbor back to the chart. We played Guess My Number by asking clues like, “Is there a 5 in the ones place?” Or “Is there a 3 in the tens place?” As skills began to settle in place we started, to solve puzzles of cut outs from the 100’s chart.  Students had to figure out what were the numbers in the empty spaces in the cut out given one 2 digit number as a clue.  IT WAS TRICKY in the beginning.  But many of the children became very proficient figuring out what number was both directly above and/or diagonally above a given number without looking at a 100’s chart.  It really gave them the opportunity to internalize how our number system works.