Kindergarten · Counting & Cardinality · MAT-K-COUNT-007
Count to 20
Recite the whole-number sequence from 1 through 20 in order.
Learning objectives
What you should be able to do
- Recite the whole-number sequence from 1 through 20 in order.
- Continue counting across the transition from 9 to 10 and from 19 to 20.
- Recognize teen-number names as part of one continuous counting sequence.
Prerequisite check
Make sure the foundation is ready.
Checks the first half of the sequence.
Checks counting-on readiness.
Learn
Build the idea from meaning, not memorization.
The number sequence continues beyond ten
Ten is not an ending. After 10 come 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20. These numbers occupy the next positions in the same one-more sequence.
Teen numbers are one ten plus extra ones
Eleven through nineteen are often called teen numbers. Their names can sound irregular, but each one is one more than the number immediately before it. Later, place value will show them as one group of ten plus some ones.
Crossing a decade does not change the rule
The move 9 → 10 and the move 19 → 20 still mean one more. Although the written numeral gains or changes digits, the amount changes by exactly one.
Break long counting into chunks
If the full sequence feels long, practice 1–5, 6–10, 11–15, and 16–20, then connect the chunks. The final goal is a smooth continuous sequence.
Interactive math lab
Change it. See what stays true.
Number Line Explorer
Move along the number line.
4 is one less. 5 and 6 is one more.
- sequence build
- teen number match
- cross ten hop
- find missing number
Worked examples
Twenty different ways to see the concept work.
Count 1 through 10.
1,2,3,4,5,6,7,8,9,10This is the known first segment.
Continue after 10 with three numbers.
11,12,13Eleven follows ten, then twelve, then thirteen.
Count 11 through 15.
11,12,13,14,15Each step is one more.
Count 16 through 20.
16,17,18,19,20The sequence reaches twenty.
What comes after 10?
11Eleven is one more than ten.
What comes after 12?
13Thirteen follows twelve.
What comes after 15?
16Sixteen follows fifteen.
What comes after 19?
20Twenty is one more than nineteen.
Fill: 9,10,__,12.
11Eleven is between ten and twelve.
Fill: 14,15,__,17.
16Sixteen is between fifteen and seventeen.
Fill: 18,19,__.
20Twenty follows nineteen.
Count from 8 to 13.
8,9,10,11,12,13The one-more rule continues through 10.
Count from 13 to 18.
13,14,15,16,17,18Starting in the teens works like any other starting point.
Which comes first: 17 or 18?
17Seventeen is one position earlier.
Which comes later: 11 or 14?
14Fourteen is farther along the sequence.
A child says 12,13,15. What is missing?
14Fourteen must come between thirteen and fifteen.
A child says 18,19,21 when counting only to 20. Correct the sequence.
18,19,20Twenty follows nineteen.
How many one-more steps from 15 to 18?
315→16 is 1, →17 is 2, →18 is 3.
Start at 10 and take five forward steps.
1510→11→12→13→14→15.
Explain why 20 belongs after 19.
20 is one more than 19The same counting rule applies at the end of the range.
Practice
Guided practice with hints
01Count 10 to 14.
Hint: Start at 10 and move one at a time.
Answer: 10,11,12,13,14
02What comes after 17?
Hint: Say 16,17 and continue one more.
Answer: 18
03Fill 11,12,__,14.
Hint: Which number lies between 12 and 14?
Answer: 13
04Count from 18 to 20.
Hint: Continue one-more twice.
Answer: 18,19,20
05What comes after 9?
Hint: This is the first two-digit number.
Answer: 10
06What comes after 19?
Hint: The next decade begins.
Answer: 20
Practice
Independent practice
01Count 11 through 15.
Answer: 11,12,13,14,15
02Count 16 through 20.
Answer: 16,17,18,19,20
03What comes after 13?
Answer: 14
04What comes after 19?
Answer: 20
05Fill 15,16,__,18.
Answer: 17
06Which comes later: 12 or 16?
Answer: 16
07Count from 9 to 12.
Answer: 9,10,11,12
08How many forward steps from 17 to 20?
Answer: 3
Common mistakes
Learn to catch the error, not just the answer.
Practice linking 8,9,10,11,12 so ten becomes a bridge rather than an endpoint.
Use numeral cards while speaking the sequence to connect names with positions.
Mark 20 as the target endpoint and stop when it is reached.
Applications & challenge
Use the idea beyond a single exercise.
Applications
- Count 20 steps during a movement activity.
- Place number cards 1–20 along a wall and walk the sequence while saying each name.
Challenge problems
Start at 7 and count nine forward steps. Where do you land?
16
What two numbers are missing: 12,__,14,15,__,17?
13 and 16
Explain what is the same about 9→10 and 19→20.
Both moves increase the quantity by exactly one.
Break 1–20 into four groups of five number names.
1–5, 6–10, 11–15, 16–20.
Flashcards
Retrieve it from memory.
Flashcards
Card 1 of 6
Game mode
Path to Twenty
Complete missing sections of a 1–20 path so a character can reach 20.
Practice
Mastery check
01Count from 1 through 20.
Answer: 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20
02What comes after 10?
Answer: 11
03What comes after 19?
Answer: 20
04Fill 13,14,__,16.
Answer: 15
05Count from 15 to 20.
Answer: 15,16,17,18,19,20
06Which comes first: 18 or 19?
Answer: 18
07What does each forward step change?
Answer: It increases the number by one.
08Explain why 20 follows 19.
Answer: Twenty is exactly one more than nineteen.
Terminology
Words to know
- teen numbers
- The whole numbers 13 through 19; in early learning, 11 and 12 are often practiced with them as the 11–19 sequence.
- twenty
- The whole number that comes immediately after nineteen.
- forward
- Toward larger numbers in the counting sequence.
- one more
- Exactly one greater than a given number.
Continue learning
Connected concepts
Curriculum references
Standards and instructional references
California Common Core State Standards for Mathematics — Kindergarten Counting & Cardinality
Standards progression for counting, cardinality, and comparison.