SWBAT use manipulatives to add and subtract larger numbers and solve word problems.

Students need time to practice new skills. They have been introduced to addition and subtraction of double-digit numbers. Today's groups will allow for practice of these skills.

10 minutes

Students will begin today with a math facts practice page. These can easily be created on Mathfactcafe.com to meet the needs of your students at any given time during the year. I give students 25 mixed addition and subtraction facts to complete in 2 minutes. I time them as they work. At the end of 2 minutes I ask students to stop and switch their pencil for a marker or colored pencil. Together we correct the page and students see how they did.

I want students to see how well they are progressing with fluency with math facts. Fluency with math facts is important (2.OA.B.2 ) as students begin to work with larger numbers. If they still need to count 9 + 6 every time they see it, even in a 2 digit number, their progress with math will be much slower. Students need to be able to quickly know the answer to the math facts so that they can concentrate on the harder problem and not get stuck on the simple facts.

45 minutes

Today the students work in centers. They visit 3 centers during the 45 minute block. I take 5 minutes at the beginning to review center expectations, (to help our partners, to work quietly - in a whisper voice, to do our best). I explain the 3 centers. With explanations and transitions students have about 12 minutes at each center.

Center 1: Here students use the base 10 houses to add and subtract 2-digit numbers. Students have been introduced to this strategy in the past couple lessons. Students work with partners to build the numbers, carry out the addition or subtraction, and record their answers. I post the problems on the board for students to build and solve.

Center 2: Students work in a small group to solve math challenge word problems . They think of possible strategies for solving the problems and then try them out. Students share their findings. At this center I put base ten houses and blocks, number lines, and number grids to encourage students to model the problem with mathematics (MP4), and make sense of the problems and persevere in solving them (MP1).

Center 3: Students review what they have learned about 2D and 3D shapes by building structures out of pipe cleaners and marshmallows to meet the provided descriptions Shape Building Directions.pdf. It is important on a regular basis to revisit terms, and skills learned at different parts of the year. If something is taught in November, it should be revisited periodically in a center, or occasional lesson to make sure that the concept is one that students still remember and can use when needed.

I divide the students up and send 6 students to each center. Today I have chosen to group heterogeneously to allow students to support one another's learning and understanding. I spend most of my time working with students at the base 10 houses to make sure that students understand the concept of modeling with the base ten blocks and then solving the problems. (I am fortunate on this day to have a parent support person to work at the challenge center. The final center is independent.)