Mathematics · Class 1
Numbers 10 to 20
Learn Numbers 10 to 20 with notes, examples, and practice questions.
3 sections15–25 min read5 MCQs · 2 examples
Chapter Overview
The number 14 means 1 ten and 4 ones. Its value is 10 + 4.
Numbers 10 to 20 develops the idea of tens and ones. Children read, write, compare, order, and build teen numbers using one group of ten and extra ones.
Tens and Ones
- Ten single objects can be bundled to make 1 ten.
- 11 is 1 ten and 1 one; 19 is 1 ten and 9 ones.
- 20 is 2 tens and 0 ones.
- The first digit in 16 tells the tens; the second digit tells the ones.
Comparing Teen Numbers
- All numbers from 10 to 19 have 1 ten, so compare their ones.
- 20 is greater than every number from 10 to 19.
- Count forward for ascending order and backward for descending order.
- Use a number line to find one more and one less.
Solved Examples
Step-by-step solutions — read each step before checking the final answer.
Make a Teen Number
How many tens and ones are in 17?
- 1Separate 17 as 10 + 7.
- 210 is one group of ten.
- 3The remaining 7 are ones.
Answer
1 ten and 7 ones
Compare Numbers
Which is greater: 13 or 18?
- 1Both numbers have 1 ten.
- 2Compare the ones: 8 is greater than 3.
- 3Therefore 18 is greater than 13.
Answer
18
Key Points to Remember
- ✓ Ten ones make one ten
- ✓ Teen numbers contain one ten and some ones
- ✓ 20 contains two tens
- ✓ Compare tens first, then ones
Exam Tips
- • Draw a bundle for each ten and dots for ones
- • Do not reverse digits when writing teen numbers
- • Say the number aloud after writing it
Practice MCQs — Numbers 10 to 20
Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.
Question 1 of 5Score: 0/0
How many tens are in 16?