SWBAT identify, write, count, and represent the number 15.

Students enjoy lots of hands-on practice building 15 and the concept of a ten and extra ones.

5 minutes

We begin our lesson with our latest Harry Kindergarten YouTube video, "Numbers in the Teens They Have a Group of Ten," which gets the kids excited about math--we just love Harry Kindergarten songs--and it also stresses the place value aspect of teen numbers, showing the row of ten under the tens place (MP.4). It's a nice visual as we sing the catchy song.

The students like it so much that we play it and sing along a second time.

40 minutes

We are thrilled to practice 15 with our watercolor 15s. As I model how to watercolor 15, I stress the importance of carefully counting while painting each little dot on the 15s (MP.6) before colorfully painting the background numbers, noting the importance of precision in the context of our watercolor painting. I also stress that while watercolor painting is pretty, relaxing, and really fun, what's cool about this kind of watercolor painting is that we are enjoying our paints, but we're painting the quantity 15 within the big numbers that make "15" (MP.2). The kids are so excited to start this practice.

Next, our gluing teen numbers activity is so much fun, and I am again thrilled to use Carolyn McCleary's free download, Breaking Numbers Into Tens and Ones, to practice building 15. I use the blank ten frames and the kiddos have a lot of little dots to count and glue into a 10-frame before gluing an extra 5 dots on a second 10-frame. (Students can punch out their 5 extra dots, but we have a large number of pre-cut dots ready to glue.) This activity allows students to count out that group of ten, stressing the essence of K.NBT.1--really practicing the 10 in that group of 10--and then gluing down the extra 5 dots. Then, students get to notate their 1 group of 10 and 5 extra ones, stressing the use of the double ten-frame to really visualize the 15 (MP.5).

Our rainbow writing 15 includes a double 10-frame to dot the quantity with marker (MP.2) as well as write the sequence of teen numbers leading up to 15. In this way, students can count up to 15, seeing the sequence and the pattern with the 1 group of 10 that stays the same, and the extra ones growing by one with each successive number (MP.7). This keeps us busy practicing our teen numbers, but allows us to be precise (MP.6), tie quantities to written numbers (MP.2), and notice patterns.

This is our first time adding a little "snack" to our teen number practice! Each kiddo in the snack group gets 10 mini marshmallows to count and then "trade" for a pretzel stick for 10. They giggle as they count! (Again, this counting the 10 marshmallows to "trade" for a pretzel stick reinforces the concept behind K.NBT.1 with the 10 individual items to combine for a group of 10. Fun stuff!) I tell the kids that since they counted their 10 marshmallows so carefully (MP.6), I'll let them eat their 10 marshmallows. The kids like up their pretzel 10-stick with the 5 extra marshmallows to show 15 (MP.4). They show their model of 15 to two friends, and then they enjoy their snacks!

Over at the "All about 15" table with me, we work on counting 10 unifix cubes and then joining them to a row of 10, and carefully, precisely counting out 5 extra ones (MP.6). We talk the entire time we are completing our recording sheet, discussing how 15 is a completely full 10-frame with a full row of 5 extra dots (or happy faces) on a second 10-frame, stressing the tools and how they help us organize our quantity (MP.5, MP.4). While a teacher could choose to do this sheet as a whole-group activity, the interaction among our small group of roughly 6 students and a teacher is critical for really checking students' understanding and making the connections between the blocks, pictures, and numbers (MP.2).

5 minutes

As we wrap up math for the day, it's hard to miss our giant "drying" area, where work is taking up half of our "meeting spot" by the calendar, with a bunch of different ways to practice 15 inadvertently displayed for anyone to see. The students' pride is hard to miss. I ask the kiddos about their favorite part of the lesson--as we always do--and the kids loved the snack, the newest part of our practice. I'm not surprised--we love food, and counting the marshmallows is a huge hit!