Tens and Ones Exercise for Grade 1

Complete exercises on understanding tens and ones in place value with detailed examples and practice activities.

Tens and Ones Exercise
1 Understanding Tens and Ones
TENS
10
One ten equals 10 ones
ONES
1
Individual units
10
Key Definitions:

Tens: Groups of 10 ones (10, 20, 30, etc.).

Ones: Individual units (1, 2, 3, etc.).

Place Value: The value of a digit based on its position in a number.

Standard Form: Writing numbers in their normal format (e.g., 23, 45).

Expanded Form: Writing a number as the sum of its place values (e.g., 23 = 20 + 3).

Tens and Ones Method:
  1. Identify the number you want to break down
  2. Count how many groups of 10 are in the number
  3. Count how many ones are left over
  4. Express the number as tens and ones
  5. Verify by adding tens and ones together
2 Place Value Understanding
Tens Place
2
Ones Place
3
Tens
20
+
Ones
3
=
23
Core Rules:

• Tens Rule: Each digit in the tens place represents groups of 10

• Ones Rule: Each digit in the ones place represents individual units

• Position Rule: The leftmost digit is in the tens place, rightmost in the ones place

• Value Rule: The total value equals (tens × 10) + (ones × 1)

Tip 1: Count by tens to understand the value of tens place.
Tip 2: Remember: 1 ten = 10 ones.
Tip 3: Always check that your tens and ones add up to the original number.
Detailed Summary: Tens and Ones
Number = (Tens × 10) + (Ones × 1)
Place Value Formula
Core Concepts and Keywords:

Tens: The place value position that represents groups of 10 (leftmost digit in two-digit numbers).

Ones: The place value position that represents individual units (rightmost digit).

Place Value: The value of a digit based on its position in a number.

Standard Form: Writing numbers in their normal format (e.g., 15, 28, 43).

Expanded Form: Writing a number as the sum of its place values (e.g., 23 = 20 + 3).

Base-10 System: Our number system where each place value is 10 times the previous one.

Regrouping: Converting 10 ones into 1 ten when necessary.

Decomposition: Breaking down numbers into their place value components.

Core Rules and Principles:

• Position Rule: Tens are in the left position, ones in the right position.

• Value Rule: Each ten is worth 10 ones.

• Base-10 Rule: Our number system uses groups of 10.

• Decomposition Rule: Any two-digit number can be broken into tens and ones.

• Composition Rule: Tens and ones can be combined to form the original number.

Step-by-Step Method:
  1. Step 1: Look at the two-digit number you want to analyze
  2. Step 2: Identify the digit in the tens place (leftmost digit)
  3. Step 3: Identify the digit in the ones place (rightmost digit)
  4. Step 4: Convert the tens digit to its actual value (multiply by 10)
  5. Step 5: Keep the ones digit as its actual value
  6. Step 6: Verify by adding tens and ones to get the original number
Tip 1: Use physical objects like blocks to visualize tens and ones.
Tip 2: Count by tens: 10, 20, 30, 40, etc.
Tip 3: Remember: the left digit is always tens, the right digit is always ones.
Tip 4: Practice with numbers 10-99 to master the concept.
Common Mistakes: Confusing tens and ones positions, forgetting that tens are worth 10 times their digit.
Memory Aid: "Tens are tall, ones are small" - tens have more value.
If Number = AB, then A = Tens and B = Ones
Tens and Ones Formula
Example
34

3 tens = 30

Example
57

7 ones = 7

Example
28

2 tens = 20

Examples and Practice Exercises
3 Simple Examples
Example 1: Number 15
Break down 15 into tens and ones
Tens
10
+
Ones
5
=
15
10
Step 1: Identify the number

We have the number 15

Step 2: Find tens and ones

15 has 1 ten (10) and 5 ones (5)

Step 3: Verify

10 + 5 = 15 ✓

15 = 1 ten + 5 ones
4 Advanced Examples
Example 2: Number 42
Break down 42 into tens and ones
Tens
40
+
Ones
2
=
42
10
10
10
10
Step 1: Identify the number

We have the number 42

Step 2: Find tens and ones

42 has 4 tens (40) and 2 ones (2)

Step 3: Verify

40 + 2 = 42 ✓

42 = 4 tens + 2 ones
5 Verification Exercises
Example 3: Number 27
Break down 27 into tens and ones and verify
Tens
20
+
Ones
7
=
27
10
10
Step 1: Identify the number

We have the number 27

Step 2: Find tens and ones

27 has 2 tens (20) and 7 ones (7)

Step 3: Verify

20 + 7 = 27 ✓

Step 4: Write in expanded form

27 = 20 + 7

27 = 2 tens + 7 ones = 20 + 7

Questions & Answers

Question: Why do we say "tens" and "ones"? What's the difference?

Answer: Great question! The names tell us how much each digit is worth:

  • Tens: Each ten is worth 10 ones (so 1 ten = 10 ones)
  • Ones: Each one is worth exactly 1 unit
  • Position: Tens are in the left position, ones in the right position

For example, in the number 23: the 2 is in the tens place (worth 20) and the 3 is in the ones place (worth 3).

Question: How can I help my child understand tens and ones at home?

Answer: Here are some effective home activities:

  1. Use everyday objects: Bundle 10 straws or pencils together to show a ten
  2. Draw representations: Draw long rectangles for tens and small squares for ones
  3. Count by tens: Practice counting 10, 20, 30, 40, etc.
  4. Number games: Call out numbers and have your child identify tens and ones
  5. Real-world examples: Point out tens and ones in house numbers, ages, etc.

Make it fun and hands-on for better understanding!

Question: What if I have the number 30? How many tens and ones are there?

Answer: Let's break down 30 step by step:

  1. Step 1: Look at the number 30
  2. Step 2: The 3 is in the tens place (3 tens = 30)
  3. Step 3: The 0 is in the ones place (0 ones = 0)
  4. Step 4: So 30 = 3 tens + 0 ones

Even though there are 0 ones, we still count them! So 30 has 3 tens and 0 ones.