This exercise introduces the fundamental concept of converting tens and ones into standard form. Students practice the basic skill of recognizing place value components and writing numbers in standard form, which is essential for developing number sense.
Standard form: Writing a number using digits (e.g., 17)
Place value: The value of a digit depends on its position in the number
Note: In grade 1, we focus on tens and ones. Each ten represents 10 ones.
- Count the tens: 1 ten = 10
- Count the ones: 7 ones = 7
- Add tens and ones together: 10 + 7 = 17
1 ten = 1 × 10 = 10
7 ones = 7 × 1 = 7
10 + 7 = 17
The standard form of 1 ten and 7 ones is 17
• Place value: Tens place represents groups of 10
• Standard form: Write number using digits
• Addition: Combine tens and ones values
• Practice Tip: Use base ten blocks to visualize: 1 long rod (ten) and 7 small cubes (ones)
- 2 tens and 3 ones = 23
- 1 ten and 9 ones = 19
- 4 tens and 0 ones = 40
- Each ten is worth 10 ones
- The tens digit goes in the tens place (second from right)
- The ones digit goes in the ones place (rightmost)
Q: What if I have more than 9 ones?
A: Regroup 10 ones as 1 ten. For example, 2 tens and 13 ones = 3 tens and 3 ones = 33.
Q: How do I write 0 tens and 7 ones?
A: That's just 7 ones = 7. We don't usually write 07, just 7.
Digit analysis: Breaking down a number to identify tens and ones
Note: In any two-digit number, the left digit is tens and the right digit is ones.
- Identify the tens digit: leftmost digit
- Identify the ones digit: rightmost digit
- State the number as tens and ones
In 49, the tens digit is 4
In 49, the ones digit is 9
49 = 4 tens and 9 ones
49 represents 4 tens and 9 ones
• Position rule: Left digit is tens, right digit is ones
• Value rule: Tens digit × 10 + ones digit
• Representation: Show as groups of tens and ones
• Practice Tip: Count by tens: 10, 20, 30, 40, then add ones: 41, 42, 43, 44, 45, 46, 47, 48, 49
- 34 = 3 tens and 4 ones
- 78 = 7 tens and 8 ones
- 60 = 6 tens and 0 ones
- Always read from left to right: tens first, then ones
- 49 means 4 groups of 10 and 9 individual units
- Count by tens first, then count ones
Q: What if the number is less than 10?
A: Single-digit numbers have 0 tens and the number as ones. For example, 6 = 0 tens and 6 ones.
Q: How do I know which digit is tens?
A: In a two-digit number, the left digit is always the tens place.
Base ten blocks: Visual tools representing tens (long rods) and ones (small cubes)
Note: Each tens block equals 10 ones blocks. This helps visualize place value.
- Count the tens blocks and multiply by 10
- Count the ones blocks
- Add the values together
3 tens blocks = 3 × 10 = 30
5 ones blocks = 5 × 1 = 5
30 + 5 = 35
The standard form is 35
• Base ten concept: Each tens block equals 10 ones
• Counting: Separate tens and ones before adding
• Standard form: Write total as a number
• Practice Tip: Draw the blocks to visualize: 3 long rectangles and 5 small squares
- 2 tens and 4 ones blocks = 24
- 5 tens and 0 ones blocks = 50
- 1 ten and 9 ones blocks = 19
- Each tens block is worth 10 individual units
- Count tens first, then add ones
- Visual representation helps understand place value
Q: Can I trade 10 ones blocks for 1 tens block?
A: Yes! This is called regrouping. 10 ones = 1 ten.
Q: What if I have 10 tens blocks?
A: 10 tens = 1 hundred. In grade 1, we focus on tens and ones.
Expanded form: Writing a number showing the value of each digit (e.g., 68 = 60 + 8)
Note: This shows the actual value each digit contributes to the whole number.
- Identify the tens digit and its value
- Identify the ones digit and its value
- Write as a sum of these values
6 in the tens place = 6 × 10 = 60
8 in the ones place = 8 × 1 = 8
68 = 60 + 8
68 in expanded form is 60 + 8
• Place value: Each position has a specific value
• Expanded form: Shows value of each digit separately
• Standard form: The usual way to write numbers
• Practice Tip: Expanded form helps understand what each digit represents
- 35 = 30 + 5
- 82 = 80 + 2
- 40 = 40 + 0
- Expanded form shows the actual value of each digit
- Tens digit × 10 + ones digit × 1
- This connects to standard form: 60 + 8 = 68
Q: Why do we learn expanded form?
A: It helps understand place value and makes addition/subtraction easier.
Q: Can I write expanded form for single digits?
A: Yes! For example, 7 = 0 + 7 or just 7.
Place value chart: Organizes digits by their place (tens, ones)
Note: Charts help organize thinking about place value and make it easier to understand.
- Identify the tens digit
- Identify the ones digit
- Fill the chart accordingly
In 84, the tens digit is 8
In 84, the ones digit is 4
Tens: 8, Ones: 4, Total: 84
Tens: 8, Ones: 4, Standard Form: 84
• Organization: Charts help organize place value thinking
• Position rule: Left digit is tens, right digit is ones
• Value calculation: Digit × place value
• Practice Tip: Use charts to double-check your work
- For 45: Tens=4, Ones=5
- For 80: Tens=8, Ones=0
- For 27: Tens=2, Ones=7
- Charts help organize thinking about place value
- Always fill tens first, then ones
- Check that your chart adds up to the original number
Q: Do I need to use a chart for every problem?
A: Not always, but charts are helpful when learning or checking work.
Q: What if I have more than two digits?
A: Grade 1 focuses on tens and ones. Later grades add hundreds, thousands, etc.