SWBAT identify the complements for the numbers 10, 20, and or 100.

Students will use dice to roll a number and then find the complement to make 10, 20 or 100.

10 minutes

I start by having the students sit in a circle on the carpet. I will be using sets of ten and twenty beads that I have made. You will be able to see from the video who they are made. You can also just get beads and a pipe cleaner and make the same tool.

*"We have been working on complements of 20. I want you to practice your fluency with this by playing a partner game with this 20 stick. You will face your partner and hide some beads and show some beads (see video). Then you will switch roles and do it again. The idea is that your are telling your partner the number of hidden beads as quickly as you can."*

I have one student who is still working on her fluency with complements of ten. While the students were working on 20s, I worked with her and used a ten stick.

In this Complements of 20 activity, the students are making sense of the number of beads and their relationship to the complements of 20 (CCSS.MATH.PRACTICE.MP2).

40 minutes

The students will work on the same game that they worked on in the previous lesson. Students will work on complements of 10, 20, or 100. The above link gives a detailed explanation of the activity. I have also included the recording sheet Math Make 10 20 100 in the section resource. I have included an example of a student working on Complements of 20 With Dice.

The CCSS expects that 1st graders can fluently add within ten and demonstrate the ability to add with in 20 accurately (CCSS.MATH.CONTENT.1.OA.C.6). This activity also allows students the opportunity to demonstrate an understanding and fluency with complements of 100 (CCSS.MATH.CONTENT.2.NBT.B.5). This is a 2nd grade standard but many first graders can do this by this point of the year.

10 minutes

You may have some students who are ready for more of a challenge. If this is the case, I would have them work on complements of 1,00o and 500. I have included the recording sheet (Math Make 100 500 1000) and a clip of a student working on Complements of 1000 in the section resource.

* Note*: The game is played the same way and uses the place value dice up to 1000. I have included a link that shows you the dice. This is not meant for you to order from this company but gives you an idea of what you will need. I would search the internet for the best price.

If students are working on 500, they will have to use addition or subtraction depending on the number they roll.

Working with these numbers and solving them using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction and relating the strategy to a written method is a second grade expectation (CCSS.MATH.CONTENT.2.NBT.B.7). However, you need to know your students because it is often that you will have a few that are ready for this developmental jump.

5 minutes

I will ask the students to meet me on the carpet and hand out their sheet for today's Mad Minute exercise. This routine was introduced in a previous lesson. Please check out the link to get a full overview of this routine.

I want to really focus on fact fluency and build upon the students ability to solve within ten fluently (CCSS.MATH.CONTENT.1.OA.C.6). I am going to use the Mad Minute Routine. This is a very "old school" routine, but I truly feel students need practice in performing task for fluency in a timed fashion. Students need to obtain fact fluency in order to have success with multiplicative reasoning. Students who don't gain this addition fact fluency by the end of 2nd grade tend to struggle with the multiplicative reasoning in third. Having this fluency also allows them to work on more complex tasks because the have the fact recall to focus on the higher level concepts.