Step 1 I used place value blocks and made a group of 25 and a group of 18. When I counted them I had 3 tens and 13 ones which is 43. Step 2 I then wanted to remove blocks until there were only 14 left. I removed blocks until there were 20 left. Step 3 Since I have two tens I need to trade a ten for 10 ones. Step 4 After I traded it, I removed blocks until there were only 14 remaining. Step 5 My answer was the number of blocks that I removed. I removed 2 tens and 9 ones. That’s 29. My equation is 25 + 18 – ___ = 14. Student 2 I used a number line. I started at 25 and needed to move up 18 spots so I started by moving up 5 spots to 30, and then 10 spots to 40, and then 3 more spots to 43. Then I had to move backwards until I got to 14 so I started by first moving back 20 spots until I got to 23. Then I moved to 14 which were an additional 9 places. I moved back a total of 29 spots. Therefore there were a total of 29 students left in the cafeteria. My equation is: 25 + 18 – ___ = 14. Student 3 Step 1 I used a hundreds board. I started at 25. I moved down one row which is 10 more, then moved to the right 8 spots and landed on 43. This represented the 18 more students coming into the cafeteria. Step 2 Now starting at 43, I know I have to get to the number 14 which represents the number of students left in the cafeteria so I moved up 2 rows to 23 which is 20 less. Then I moved to the left until I land on 14, which is 9 spaces. I moved back a total of 29 spots. That means 29 students left the cafeteria.
Constructing Task Individual Representing numbers, Addition and Subtraction MGSE2.OA.1 MGSE2.OA.2 MGSE2.NBT.5 MGSE2.MD.8 Solve and verify story problems using various strategies. Practice Task Individual Estimation, Mental math strategies MGSE2.OA.2 MGSE2.NBT.5 Practice addition and mental math estimation skills. Constructing Task Large Group, Small Groups Estimation, Mental math strategies MGSE2.OA.2 MGSE2.NBT.5 Develop efficient ways to group numbers and or develop compensation strategies for mental addition and subtraction; and practice explaining strategies. Practice Task Large Group Addition to 100 MGSE2.OA.2 MGSE2.NBT.5 Develop mental math strategies in a game adding 2-dgit numbers to 100. Scaffolding Task Individual Multi-digit addition with regrouping MGSE2.OA.1 MGSE2.OA.2 MGSE2.NBT.5 Use mental math strategies and/or manipulatives to solve 2-digit story problems. Constructing Task Large Group, Partners Multi-digit addition with regrouping MGSE2.OA.1 MGSE2.OA.2 MGSE2.NBT.5 Use mental math strategies and/or manipulatives to solve 2-digit story problems. MGSE2.OA.1 MGSE2.OA.2 Students demonstrate developing understanding of addition and subtraction Constructing Task Individual Addition with money MGSE2.OA.1 MGSE2.OA.2 MGSE2.NBT.5 MGSE2.MD.8 Further develop understanding of the concept of addition while solving problems by adding prices of purchases using only coin amounts. Practice Task Large group, Partners Modeling addition with money MGSE2.OA.1 MGSE2.OA.2 MGSE2.NBT.5 MGSE2.MD.8 Add dollar amounts of purchases using the $ symbol correctly. Scaffolding Task Large group, Partners Multi-digit subtraction with regrouping MGSE2.OA.1 MGSE2.OA.2 MGSE2.NBT.5 Apply knowledge of addition and subtraction as inverse operations to develop a personal strategy for regrouping/trading in subtraction problems.