Standard form: Writing a number using digits (e.g., 34)
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: 3 tens = 30
- Count the ones: 4 ones = 4
- Add tens and ones together: 30 + 4 = 34
3 tens = 3 × 10 = 30
4 ones = 4 × 1 = 4
30 + 4 = 34
The standard form of 3 tens and 4 ones is 34
• 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: 3 long rods (tens) and 4 small cubes (ones)
- 2 tens and 5 ones = 25
- 4 tens and 0 ones = 40
- 1 ten and 9 ones = 19
- 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 57, the tens digit is 5
In 57, the ones digit is 7
57 = 5 tens and 7 ones
57 represents 5 tens and 7 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, 50, then add ones: 51, 52, 53, 54, 55, 56, 57
- 23 = 2 tens and 3 ones
- 89 = 8 tens and 9 ones
- 40 = 4 tens and 0 ones
- Always read from left to right: tens first, then ones
- 57 means 5 groups of 10 and 7 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
4 tens blocks = 4 × 10 = 40
6 ones blocks = 6 × 1 = 6
40 + 6 = 46
The standard form is 46
• 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: 4 long rectangles and 6 small squares
- 2 tens and 3 ones blocks = 23
- 5 tens and 0 ones blocks = 50
- 1 ten and 8 ones blocks = 18
- 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
- 25 = 20 + 5
- 73 = 70 + 3
- 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 92, the tens digit is 9
In 92, the ones digit is 2
Tens: 9, Ones: 2, Total: 92
Tens: 9, Ones: 2, Standard Form: 92
• 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 34: Tens=3, Ones=4
- For 80: Tens=8, Ones=0
- For 17: Tens=1, 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.