Build a strong mathematical foundation with counting, number writing, addition & subtraction within 20, place value, and simple word problems. Perfect for classroom use, homeschooling, or extra practice at home.
Introduction
Number sense is the ability to understand, relate, and work with numbers. It’s the very first step in every child’s mathematical journey. Long before calculus, before algebra, even before formal addition, children must develop a feeling for what numbers mean. This worksheet is designed for children in kindergarten through second grade (ages 5–8) to strengthen that foundation in a playful, confidence‑building way.
We begin with counting — not just reciting numbers, but connecting each number to a quantity. Next, we practice writing numbers, then move to simple addition and subtraction using objects, number lines, and mental strategies. Place value (tens and ones) is introduced gently, and we finish with word problems that show how math lives in everyday situations.
For parents and teachers: let the child work at their own pace. Use real objects (buttons, blocks, snacks) alongside the worksheet. Celebrate effort, not just correct answers. The goal is to make numbers feel friendly and useful.
Learning Objectives
Count objects up to 20 and write the corresponding numeral.
Recognize and write numbers from 0 to 20.
Understand addition as putting together and subtraction as taking away.
Add and subtract within 20 using objects, drawings, or mental strategies.
Understand that two‑digit numbers are made of tens and ones.
Solve simple word problems involving addition and subtraction.
Key Concepts & Worked Examples
1. Counting and Writing Numbers
Counting means matching each object to one number word. When we count, the last number tells us how many.
Example 1 — Counting Objects
🍎 🍎 🍎 🍎 (How many apples?)
Count each apple
1, 2, 3, 4 → four apples
Write the number: 4
Answer: 4
2. Addition (Putting Together)
Addition means finding the total when groups are combined. We can use “+” and “=”.
Example 2 — Adding with Objects
🐶 🐶 + 🐶 🐶 🐶 = ?
Count the first group: 2 dogs
Count the second group: 3 dogs
Now count all together: 1,2,3,4,5 → 5 dogs
Write as number sentence: 2 + 3 = 5
Answer: 5
3. Subtraction (Taking Away)
Subtraction means finding how many are left after some are taken away. We use “–”.
Example 3 — Subtracting with Fingers
You have 7 crayons. You give away 2. How many are left?
Start with 7. Take away 2.
Count the ones left: 5 crayons.
Number sentence: 7 – 2 = 5
Answer: 5
4. Place Value (Tens and Ones)
In a two‑digit number, the first digit tells how many tens, the second how many ones.
Example 4 — Understanding 14
14 = 1 ten and 4 ones.
Draw 1 bundle of ten sticks and 4 single sticks.
10 + 4 = 14
1 ten, 4 ones
Parent / Teacher Tip: Use real objects whenever possible. Let the child touch, move, and group items. This makes abstract numbers concrete.
Practice Problems
Part A — Counting & Writing Numbers (Problems 1–10)
Count the objects and write the number in the blank.
⚽ ⚽ ⚽ (How many soccer balls?)
🍪 🍪 🍪 🍪 🍪 (cookies)
🐟 🐟 🐟 🐟 🐟 🐟 (fish)
⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ (stars)
🍌 🍌 🍌 🍌 🍌 🍌 🍌 🍌 (bananas)
Write the number that comes after 6: ___
Write the number that comes before 10: ___
How many fingers on one hand? ___
Draw 5 circles: (space for drawing) — but we just write the number 5.
Write the missing numbers: 1, 2, __, 4, 5, __, 7
Part B — Addition within 10 (Problems 11–20)
Add the numbers. You may use objects or your fingers.
3 + 2 = ?
4 + 1 = ?
5 + 3 = ?
2 + 6 = ?
7 + 2 = ?
0 + 5 = ?
4 + 4 = ?
6 + 3 = ?
1 + 8 = ?
9 + 1 = ?
Part C — Subtraction within 10 (Problems 21–30)
Subtract. How many are left?
5 – 2 = ?
7 – 3 = ?
9 – 4 = ?
6 – 1 = ?
8 – 5 = ?
4 – 0 = ?
10 – 3 = ?
7 – 7 = ?
9 – 6 = ?
8 – 2 = ?
Part D — Place Value & Word Problems (Problems 31–40)
Read carefully. Write your answer as a number or number sentence.
How many tens and ones in 17? ___ tens, ___ ones
Write 13 as "___ tens and ___ ones".
What number has 1 ten and 5 ones? ___
What number has 2 tens and 0 ones? ___
Emma has 4 red apples and 3 green apples. How many apples does she have in all? ___
There were 9 birds on a fence. 2 flew away. How many birds are left? ___
Leo had 8 toy cars. He gave 3 to his friend. How many cars does Leo have now? ___
In a garden, there are 6 butterflies and 4 bees. How many insects are there? ___
Mom baked 12 cookies. The children ate 4. How many cookies are left? ___
Ben has 1 ten and 2 ones. His sister has 1 ten and 6 ones. Who has more? Write the number for each and compare.
Quick Answer Key
1. 3
2. 5
3. 6
4. 7
5. 8
6. 7
7. 9
8. 5
9. (draw 5 circles) – just check
10. 3, 6
11. 5
12. 5
13. 8
14. 8
15. 9
16. 5
17. 8
18. 9
19. 9
20. 10
21. 3
22. 4
23. 5
24. 5
25. 3
26. 4
27. 7
28. 0
29. 3
30. 6
31. 1 ten, 7 ones
32. 1 ten, 3 ones
33. 15
34. 20
35. 7 apples
36. 7 birds
37. 5 cars
38. 10 insects
39. 8 cookies
40. Ben: 12, sister: 16, sister has more
Step-by-Step Solutions
Problem 1
Count the soccer balls: 1,2,3 → 3.
Problem 2
🍪🍪🍪🍪🍪 = 5 cookies.
Problem 3
6 fish.
Problem 4
7 stars.
Problem 5
8 bananas.
Problem 6
After 6 comes 7.
Problem 7
Before 10 is 9.
Problem 8
One hand has 5 fingers.
Problem 9
Draw 5 circles – check with child.
Problem 10
1,2,3,4,5,6,7 → missing 3 and 6.
Problem 11
3 + 2 = 5 (count on fingers: 3…4,5).
Problem 12
4 + 1 = 5.
Problem 13
5 + 3 = 8.
Problem 14
2 + 6 = 8.
Problem 15
7 + 2 = 9.
Problem 16
0 + 5 = 5 (adding zero does nothing).
Problem 17
4 + 4 = 8.
Problem 18
6 + 3 = 9.
Problem 19
1 + 8 = 9.
Problem 20
9 + 1 = 10.
Problem 21
5 – 2 = 3 (take 2 away from 5, left 3).
Problem 22
7 – 3 = 4.
Problem 23
9 – 4 = 5.
Problem 24
6 – 1 = 5.
Problem 25
8 – 5 = 3.
Problem 26
4 – 0 = 4 (taking nothing leaves 4).
Problem 27
10 – 3 = 7.
Problem 28
7 – 7 = 0 (all taken away).
Problem 29
9 – 6 = 3.
Problem 30
8 – 2 = 6.
Problem 31
17 = 1 ten + 7 ones.
Problem 32
13 = 1 ten + 3 ones.
Problem 33
1 ten + 5 ones = 15.
Problem 34
2 tens = 20.
Problem 35
4 red + 3 green = 7 apples total.
Problem 36
9 birds – 2 flew away = 7 birds left.
Problem 37
8 – 3 = 5 cars left.
Problem 38
6 + 4 = 10 insects.
Problem 39
12 – 4 = 8 cookies left.
Problem 40
Ben: 1 ten 2 ones = 12. Sister: 1 ten 6 ones = 16. 16 > 12, so sister has more.
Frequently Asked Questions
What is number sense?
Number sense is the ability to understand, relate, and work with numbers. It includes counting, recognising quantities, comparing numbers, and performing simple operations like addition and subtraction.
How can I help my child who is struggling with counting?
Use everyday objects (snacks, toys). Count them slowly and point to each. Practice counting forward and backward. Play simple board games that involve moving a piece along a numbered track.
What's the difference between addition and subtraction?
Addition puts groups together to find a total. Subtraction takes away from a group to find how many are left. Use words like "in all" for addition and "how many left" for subtraction.
When should a child know addition facts up to 10?
By the end of first grade, most children can add and subtract within 10 fluently. By second grade, they extend that to within 20. Regular practice with visual aids and games helps.
What are tens and ones?
Tens and ones are the building blocks of our number system. In the number 14, the '1' means one group of ten, and the '4' means four extra ones. Understanding this prepares children for regrouping (carrying/borrowing).
How do I use this worksheet with my child?
Let your child try a few problems, then check the answers together. Use real objects (buttons, coins) to act out problems. Praise effort and let them explain their thinking.