Ask students who feels really confident about place value - who feels really ready to move on to subtraction? Who needs some more practice with place value? (Split into 2 groups)
Andrés C., Dayanara, Viviana, Jonathan V., Andy, Ruby, Hugo, Beatriz, Andrés G., Victoria, Miguel, Erika, Iván, Enrique, Jonathan P., Michelle, Alberto, Jesus
-- Explain game:
- Each person gets a calculator (get calculators after giving directions)
- List 3-digit numbers on board (289, 405, 112, 765, 894, 500, 371, 678, 923, 238)
1. Person who comes first alphabetically goes first. Choose 1 number to eliminate (get rid of) in the 3-digit number
2. Person who didn't choose has to eliminate that number by subtracting or adding.
- Take turns choosing and eliminating numbers
* If you run out of numbers, make up your own. Try a 4-digit number for a challenge.
- Record all "moves" on sheet - only one scorekeeper per pair is ok.
- Model 2-3 examples with students. 874, choose student to select a number to eliminate. Ask a volunteer for 1 way to eliminate. Ask for another volunteer with another way to eliminate.
* TOUCH ON PLACE VALUE - if you're trying to eliminate a number in the 100's or 10's column, you're going to have to add 0's - try to get the students to come up with this.
Get calculators, get partners, and play the game!
Yesenia, Jacqueline, Yuritzi, Diana C., Ricardo, Annette, Axel, Juan, Alexis
-- Take 3 boxes of base-ten blocks to carpet. Silently (so I can explain directions to the other students) make the numbers listed on the board with base-ten blocks. Record how you made them in base-ten shorthand on a piece of paper in your notebook.
-- After giving instructions to the other group: students put aside base-ten pieces
-- Review numbers that students made with base-ten blocks. How did you know to make it that way? What pieces did you use? Why?
-- Beanbag game (set up scoreboard and distribute beanbags to students)
- Have students take turns throwing beanbags onto scoreboard
- Once there are a few beanbags on each place value spot, have students make number using base-ten blocks and record their representations on a recording sheet.
- Have students represent numbers with symbols (numbers)
- Repeat, encouraging students to use base-ten blocks less frequently
- As students become comfortable with making and representing numbers, give them bigger numbers to make and represent by arranging beanbags on scoreboard
Closing -- Have a representative from each group explain what they did to the other group. Ask students to describe some things they learned today.