The purpose of this activity is for students to use fingers to represent numbers 11–19. Initially students represent numbers 5–10 to recall the structure of 5 ones and some more ones for these numbers. Students then work with a partner to represent numbers 11–19, which highlights that these numbers are 10 ones and some more ones. The purpose of the Activity Synthesis is to describe numbers 11–19 as “10 and _____.” In future lessons, numbers 11–19 will also be represented as expressions: and equations: .

• Invite previously identified students to share 17 with their fingers.
• “How many fingers is _____ holding up?” (10)
• “How many fingers is _____ holding up?” (7)
• “How many fingers are they holding up altogether?” (17)
• “10 and 7 is 17.”

The purpose of this activity is for students to recognize numbers 11–19 on images of fingers and represent the same numbers on 10-frames. Students may count each finger and each counter as they create groups with the same number of counters as fingers. They may make a connection between all the fingers on two hands and a full 10-frame and use that connection to make a group with the same number by filling in a 10-frame and then attending to how many additional fingers there are (MP7). If students represent numbers on the 10-frame without counting, ask, “How do you know you have the same number of counters and fingers without counting them?”

In the Activity Synthesis, students discuss and compare different ways to arrange the additional counters that do not fit on the 10-frame. While students may arrange their additional counters in a way that makes sense to them, these materials will show the additional counters arranged in rows under the 10-frame.

MLR8 Discussion Supports. Invite each partner to say the number that is displayed. This gives both students an opportunity to produce language. Listen for and clarify any questions.

Advances: Conversing Representation: Develop Language and Symbols. Synthesis: Make connections between representations visible by using gestures or labeled displays as students describe where they see the 10 fingers from the image in their representation. If time permits, ask students what the hand with 0 fingers showing represents.
Supports accessibility for: Conceptual Processing

• Display previously selected arrangements, such as:

• “What is the same about how _____ and _____ showed 14? What is different?” (They both used counters. They both filled in the 10-frame. _____ put the extra counters underneath the 10-frame and _____ put the extra counters next to the 10-frame.)
• “Where do you see 10 in each person’s work?” (There are 10 counters in each 10-frame.)
• “Where do you see 4 in each person’s work?” (There are 4 counters under the 10-frame or 4 counters on the side of the 10-frame.)
• Display “14.”
• “There are 10 counters and 4 counters. There are 14 counters. 10 and 4 is 14.”

The purpose of this activity is for students to revisit Stage 2 of the Number Race center. In an earlier variation, students traced numbers 11‒20. Now they will write the numbers. Students roll a connecting cube onto the mat, identify the number it lands on, and write that number on their recording sheet. Students continue rolling and writing until one number “wins” (all of the numbers in the column are written). 

After students have written all of one number, they can finish writing the rest of the numbers or play again. Students can use different colors or writing utensils during this center. Writing numbers backwards (“reversals”) and incorrectly forming numbers is expected in kindergarten. The emphasis is on students writing a number that is recognizable to others with practice.

After they participate in the Number Race center, students choose any previously introduced stage from these centers:

• Grab and Count 
• Find the Pair
• Tower Build

• “Tell your partner something you noticed about writing the numbers 11–20.” (They all start with a 1 except 20. They all have 2 numbers. The second number gets bigger in each number. You don’t write them the way they sound. For example, fourteen sounds like we write a 4 first, but we don’t.)