Kindergarten Fall Math — Counting to 100, Subitizing, Cardinality, Shapes, and Pattern
Lesson 2 25 min math.gK.f.lesson_02

Counting from 11 to 20 — the trickiest numbers

Skills targeted
Objectives
  • Students can recite the count sequence 11 through 20 with attention to -teen pronunciation.
  • Students can extend the count from a given starting number within 1-20.
Vocabulary
eleventwelvethirteenfourteenfifteensixteenseventeeneighteennineteentwentyteen

Lesson plan

Warm-up

5 min

Read-aloud: pages 1-10 of Anno's Counting Book (Anno 1977). Children count along with each season's village scene.

Teacher moves
  • Pause at each page; point and count aloud, modeling one-to-one tagging on the picture.
  • After page 10: 'tomorrow we go higher — but those teen numbers are tricky!'
Media
M-K-F-NS-02-B Photograph
Two photographs side-by-side: (left) the open Anno's Counting Book pages 3 and 4 showing the spring village with 3 trees

Two photographs side-by-side: (left) the open Anno's Counting Book pages 3 and 4 showing the spring village with 3 trees and 4 children; (right) a child's finger touching each tree as the teacher reads. Used as a teacher-facing setup reference for the read-aloud sequence.

Direct instruction

8 min

The numbers from 11 to 20 are the tricky-teens. Most of them end in -TEEN, which means 'and ten more.' Thirteen = three + ten. Fourteen = four + ten. Let's listen carefully.

Key examples
  • Notice 11 and 12 don't follow the rule — they are eleven and twelve, special names.
    model 10, 11, 12, 13... wait — listen — THIR-teen, FOUR-teen, FIF-teen, SIX-teen, SEVEN-teen, EIGH-teen, NINE-teen, TWENTY.
    prompt Count from 10 to 20, stopping at each teen.
Checks for understanding
  • What does -TEEN mean? (ten more)
  • Which two teens are 'special' (don't follow the rule)? (eleven and twelve)
Media
M-K-F-NS-02-A Chart
Two-column chart titled 'TEEN or TY?' Left column (yellow header): 13 thir-TEEN, 14 four-TEEN, 15 fif-TEEN, 16 six-TEEN,

Two-column chart titled 'TEEN or TY?' Left column (yellow header): 13 thir-TEEN, 14 four-TEEN, 15 fif-TEEN, 16 six-TEEN, 17 seven-TEEN, 18 eigh-TEEN, 19 nine-TEEN — each number large 28-pt black numeral with TEEN ending in red bold. Right column (blue header): 30 thir-TY, 40 four-TY (with TY ending in blue bold). Bottom note: 'teen = ten more!' with arrow.

Guided practice

7 min
Tasks
  • Counting relay in pairs — partner A counts 1-10, partner B counts 11-20, then swap.
    scaffold Numeral cards 11-20 face-up on the table to support partner B.
  • Teacher says a starting number (e.g., 14); class continues to 20.

Formative assessment

2 min
Exit ticket
  • Teacher whispers a starting number 8-18 to child; child counts forward to 20.
scoring Correct sequence to 20 = mastery snapshot; 1-2 teen-pronunciation slips with self-correction = practicing; mid-sequence restart or omission = reteach

Closure

2 min
Moves
  • Children chant: 'eleven, twelve, then -TEEN, -TEEN, all the way to twenty!'
  • Preview: 'Tomorrow we play a Number Talk dot-flash game.'

Homework

5 min
Tasks
  • Practice saying the teen numbers 13, 14, 15 with a family member. Have them check pronunciation (thir-TEEN not thir-TY).

Exercises in this lesson

math.gK.f.ns.count_to_100.ex_03
Start at 14 and count to 20. (Say only the numbers from 14 to 20.)
 count on from given · diff 3
math.gK.f.ns.count_to_100.ex_04
Count by tens to 100. (10, 20, ...)
 count by tens · diff 4

Differentiation

Scaffolds
  • Pre-printed visual 11-20 strip with -TEEN syllable underlined
  • Bingo-style 1-20 board for repeated exposure
Extensions
  • Count from 11 to 30 (introduces twenty-one through thirty)
  • Count backward 20 to 11
English Learners
  • Bilingual 11-20 chart with home-language word next to English word
  • Audio listening loop of 11-20 in clear American English
Ieps 504s
  • Reduce range to 10-15 if 11-20 overwhelms
  • Visual prompt card for each numeral

Teacher notes

The -teen vs. -ty confusion (fourteen vs. forty) persists through Grade 1. At K, exposure with explicit auditory contrast is enough — do not penalize errors but always model the correct pronunciation. The 11/12 exception is genuinely tricky in English (other languages like Mandarin are more regular: shi-yi = ten-one, shi-er = ten-two). Acknowledge to EL families that English is being the irregular language here.