Complete Guide to Tens and Ones Worksheet Answers in Grade 1

Master place value: tens and ones decomposition, number breakdowns, and detailed worksheet solutions through these comprehensive exercises.

Worksheet Solutions: Exercises 1 to 3
1 Decompose numbers into tens and ones
Exercise 1
Write 47 as tens and ones.
47 = ___ tens + ___ ones
Definition:

Decomposition: Breaking a number into its place value parts. In a two-digit number, the left digit represents tens and the right digit represents ones.

Decomposition method:
  1. Identify the tens place (leftmost digit)
  2. Identify the ones place (rightmost digit)
  3. Express the number as the sum of tens and ones
Original Number
47
Tens Place
4 tens = 40
Ones Place
7 ones = 7
Step 1: Identify tens digit

The tens digit in 47 is 4, which represents 4 groups of 10

Step 2: Calculate tens value

4 tens = 4 × 10 = 40

Step 3: Identify ones digit

The ones digit in 47 is 7, which represents 7 individual units

Step 4: Write the decomposition

47 = 4 tens + 7 ones = 40 + 7

47 = 4 tens + 7 ones
Final answer:

47 = 4 tens + 7 ones

Applied rules:

• Place value: Each position in a number has a specific value

• Digit value: A digit's value depends on its position

• Number composition: A number equals the sum of its place values

2 Reconstruct number from tens and ones
Exercise 2
What number is made of 3 tens and 8 ones?
___ tens + ___ ones = ___
Definition:

Number reconstruction: Combining tens and ones to form the original number by adding their values together.

Given Parts
3 tens + 8 ones
Calculate Value
30 + 8 = 38
Final Number
38
Step 1: Calculate tens value

3 tens = 3 × 10 = 30

Step 2: Calculate ones value

8 ones = 8 × 1 = 8

Step 3: Add together

30 + 8 = 38

3 tens + 8 ones = 38
Final answer:

3 tens + 8 ones = 38

Applied rules:

• Place value addition: Add the values of each place to get the total

• Number formation: Tens value + ones value = complete number

• Commutative property: Order doesn't matter when adding (30 + 8 = 8 + 30)

3 Identify tens and ones in context
Exercise 3
There are 56 apples in a basket. How many tens and ones are there?
56 = ___ tens + ___ ones
Definition:

Contextual decomposition: Applying place value concepts to real-world situations by breaking down quantities into tens and ones.

Total Quantity
56 apples
Tens Part
5 tens = 50
Ones Part
6 ones = 6
Result
56 = 50 + 6
Step 1: Identify the number

There are 56 apples, so we decompose 56

Step 2: Find tens digit

The tens digit in 56 is 5, representing 5 groups of 10 apples

Step 3: Find ones digit

The ones digit in 56 is 6, representing 6 individual apples

Step 4: Write the decomposition

56 = 5 tens + 6 ones = 50 + 6

56 = 5 tens + 6 ones
Final answer:

56 = 5 tens + 6 ones

Applied rules:

• Real-world application: Place value applies to all counting situations

• Grouping principle: Objects are grouped in tens for easier counting

• Value preservation: Decomposition doesn't change the total amount

Tens and Ones: Complete Guide and Rules
23 = 2 tens + 3 ones = 20 + 3
Place Value Decomposition
Rule 1
Tens Place Value
Left digit × 10
Rule 2
Ones Place Value
Right digit × 1
Rule 3
Number = Tens + Ones
23 = 20 + 3
Key definitions:

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

Tens place: The leftmost digit in a two-digit number represents groups of ten

Ones place: The rightmost digit in a two-digit number represents individual units

Decomposition: Breaking a number into its component parts based on place value

Complete methodology:
  1. Identify digits: Locate tens and ones digits in the number
  2. Calculate values: Multiply each digit by its place value (10 for tens, 1 for ones)
  3. Combine parts: Add the place values together
  4. Verify: Check that the parts add up to the original number
Tip 1: Think of tens as groups of 10 objects (like 10 crayons in a box).
Tip 2: Use base-10 blocks to visualize tens (sticks of 10) and ones (individual cubes).
Tip 3: Always read from left to right: tens first, then ones.
Tip 4: Practice with real objects like beans or buttons grouped in tens.
Common errors: Forgetting to multiply by 10 for tens place, confusing tens with ones, misreading digits.
Memory aid: "Tens are bigger - they come first!" (left to right).
Place value formulas to remember:

• Two-digit number AB = A × 10 + B × 1

• Tens digit × 10 = tens value

• Ones digit × 1 = ones value

• Total number = tens value + ones value

Tens and Ones Visualization
Number Composition Analysis
Visual representation of 42 = 4 tens + 2 ones:
42 = 40 + 2
4 tens = 40
2 ones = 2

Analysis: The chart shows how tens and ones combine to form the complete number.

  • 42 = 4 tens (40) + 2 ones (2)
  • Total value = 40 + 2 = 42
  • Each part contributes to the final number

Questions & Answers

Question: I'm confused about why in the number 15, the 1 is worth 10 and not just 1. Why doesn't the 1 mean 1?

Answer: Great question! This is all about place value. The position of a digit tells us its value:

  • In the number 15, the "1" is in the tens place (the left position)
  • Any digit in the tens place is worth 10 times its face value
  • So the "1" in the tens place = 1 × 10 = 10
  • The "5" is in the ones place (the right position)
  • Any digit in the ones place keeps its face value
  • So the "5" in the ones place = 5 × 1 = 5

Think of it like this: if you had 15 dollars, you might have 1 ten-dollar bill and 5 one-dollar bills. The 1 ten-dollar bill is worth $10, not $1. That's why 15 = 10 + 5.

The place tells us how much each digit is worth: tens place = multiply by 10, ones place = multiply by 1.

Question: How can I help my child understand that 23 is not the same as 32, even though they use the same digits?

Answer: This is a common challenge! Here are effective strategies to show the difference:

  • Use manipulatives: Show 23 as 2 groups of 10 blocks + 3 individual blocks, and 32 as 3 groups of 10 + 2 individual blocks
  • Visual representation: Draw 23 as 2 long sticks (tens) and 3 dots (ones), and 32 as 3 long sticks and 2 dots
  • Real-world examples: Compare $23 vs $32, or 23 marbles vs 32 marbles
  • Position games: Have your child write the digits in different orders and calculate the values

The key insight: the position of each digit determines its value. In 23, the "2" is worth 20, but in 32, the "2" is only worth 2. Similarly, the "3" in 23 is worth 3, but in 32, it's worth 30.

Practice with base-10 blocks or drawings until the concept clicks!

Question: My child struggles with problems like "What number is 4 tens and 7 ones?" How can I make this easier?

Answer: This type of problem requires reversing the thinking process. Try these approaches:

  1. Build up gradually: Start with "What is 1 ten?" (10), then "2 tens?" (20), etc.
  2. Use concrete objects: Take 4 groups of 10 items and 7 individual items, count them all
  3. Connect to decomposition: Remind your child that if 47 = 4 tens + 7 ones, then 4 tens + 7 ones = 47
  4. Pattern recognition: Show that 3 tens + 5 ones = 35, 4 tens + 6 ones = 46, etc.

Create a simple algorithm for your child:

  • Step 1: Calculate tens value (4 tens = 40)
  • Step 2: Keep ones value (7 ones = 7)
  • Step 3: Add them together (40 + 7 = 47)

Practice with many examples until the pattern becomes automatic!

Question: What hands-on activities can I use to reinforce tens and ones concepts?

Answer: Hands-on activities make abstract concepts concrete:

  • Base-10 blocks: Use rods for tens and small cubes for ones to build numbers
  • Sticks and beans: Bundle 10 beans with rubber bands to represent tens
  • Money math: Use dimes (tens) and pennies (ones) to represent numbers
  • Folding paper: Fold paper strips into 10 sections to show tens
  • Counting collections: Group objects in sets of 10 and count the extras

Interactive games work well too:

  • Create a "number machine" where students feed in tens and ones to make numbers
  • Play "Guess my number" with tens and ones clues
  • Have students race to build numbers with manipulatives

The physical act of grouping and counting helps cement the concept!

Question: How do I explain zero in the ones place, like in 40?

Answer: Zero in the ones place can be tricky! Explain it this way:

  • Zero means none: In 40, there are 4 tens and 0 ones (no extra single items)
  • Placeholder role: The 0 holds the ones place to show there are no extra units beyond the tens
  • Visual aid: Show 4 groups of 10 with nothing left over
  • Comparison: Compare 40 (4 tens, 0 ones) with 41 (4 tens, 1 one)

Use concrete examples: if you have 40 pencils, you have 4 boxes of 10 pencils each, with no loose pencils left over. The zero tells us there are no extra pencils outside the groups of 10.

Emphasize that 40 = 40 + 0, so it's still 4 tens with no additional ones.