Discovering Teen Numbers

Overview

In this engaging 30-minute session, students will explore teen numbers (11-19) through an interactive outdoor scavenger hunt. By collecting and physically grouping natural items, they will develop a concrete understanding of these numbers as composed of ten plus some more. This multisensory approach aligns with California Kindergarten Mathematics Content Standards, encouraging foundational number sense and early place value concepts.

Grade Level

Kindergarten (Ages 5-6)

Standards Alignment

California Common Core State Standards for Mathematics, Kindergarten:

K.CC.4: Understand the relationship between numbers and quantities; connect counting to cardinality.
K.NBT.1: Compose and decompose numbers from 11 to 19 into ten ones and some further ones, e.g., 18 is 10 ones and 8 ones.
K.MP.1: Make sense of problems and persevere in solving them (through hands-on activities).
K.MP.3: Construct viable arguments and critique the reasoning of others (group discussion).

Learning Objectives

By the end of this lesson, students will:

Identify and understand teen numbers as ten plus additional ones.
Demonstrate counting skills through collecting and grouping natural items.
Verbally explain their grouping to connect quantity with teen number symbols.
Engage cooperatively in a structured outdoor learning activity.

Materials Needed

Small baskets or bags (1 per student or pair)
Clipboards with recording sheet (simple tally or drawing of items collected)
Pencils or crayons
Pre-prepared number cards (11-19)
Large ten-frame mats (optional, for grouping)
Outdoor space with accessible natural objects (leaves, stones, twigs)

Lesson Structure

1. Introduction (5 minutes)

Engage: Gather students outside or near a window with visible natural items.
Connect: Ask: “Can you say the numbers you know between 1 and 10? What happens after 10?”
Explain: Introduce teen numbers as "ten ones and some more." Show number cards 11-19.
Model: Demonstrate with a large ten-frame and natural items how “13” means 10 items plus 3 more.

2. Guided Scavenger Hunt (15 minutes)

Instructions: Students will find natural items outside to collect groups representing one teen number assigned to them (or choose one together).
Examples: One group collects 12 leaves, another 15 stones, etc. Encourage counting aloud as they collect.
Group Work: Students count out ten items first, then add extras to complete their teen number. Use ten-frame mats if available to organize and visualise.
Teacher Role: Circulate, support counting accuracy, ask probing questions (“How many did you collect? How can you group ten first?”).

3. Reflection and Sharing (7 minutes)

Group Sharing: Each student or pair takes turns showing their natural item groups with the number card.
Prompt: “How did you make your number? How many items are in the ‘ten’ group? How many are the ‘ones’?”
Math Talk: Highlight patterns noticed across different teen numbers. Reinforce that they all have one ten group plus some extra ones.

4. Closing and Takeaway (3 minutes)

Summarise key learning points: teen numbers = ten + more ones.
Encourage students to look for teen numbers or groups of tens plus some more in their environment or books.
Hand out a simple “teen number tracker” for students to take home and practice counting objects in sets of ten plus extras.

Differentiation

For advanced learners: Challenge to write the numeral symbol matching the quantity collected or create addition story problems with their items (e.g., 10 + 4 = 14).
For students needing support: Pair with a buddy, use physical counters or fingers to assist counting.

Assessment

Formative: Observe counting strategies and accuracy during scavenger hunt.
Oral feedback: Listen to student explanations and reasoning during sharing.
Student Work: Review recording sheets for understanding of grouping in tens plus ones.

Cross-Curricular Connections

Science: Observe different types of natural objects, fostering environmental awareness.
Language Arts: Use new vocabulary (teen numbers, counting, grouping) in discussion.
Social Skills: Practice teamwork and communication in pairs or small groups.

Teacher Tips

Conduct a quick safety reminder about respecting nature and students’ personal space outdoors.
Use enthusiasm and tangible objects to anchor abstract concepts for young learners.
Consider photographing groups for a visual portfolio to show progress across the “Exploring Teen Numbers Outdoors” unit.

By connecting teen numbers to real-world, hands-on experiences, students gain foundational understanding that will support their future math learning and foster a love of discovering numbers in their environment.

Teaching Instructions