Place Value: Understanding the value of each digit based on its position in a number. Each position represents a power of 10.
Rounding: Approximating numbers to make them easier to work with by replacing them with nearby numbers that are multiples of 10, 100, 1000, etc.
Digit: Any of the numerals 0-9 used to form numbers.
Place Value: The value of a digit based on its position in a number (ones, tens, hundreds, etc.).
Face Value: The actual value of a digit regardless of its position.
Rounding: Replacing a number with another number that tells about how many or how much.
Expanded Form: Writing a number as the sum of the value of each digit.
Standard Form: Writing a number in the normal way using digits.
Word Form: Writing a number using words.
• Place Value Pattern: Ones, Tens, Hundreds, Thousands, Ten Thousands... Each place is 10 times the previous place
• Rounding Rule: Look at the digit to the right of your target place: 5 or more rounds UP, 4 or less rounds DOWN
• Zero Replacement: After rounding, all digits to the right of the target place become zeros
• Comparison Method: Compare numbers from left to right, starting with the highest place value
• Expanded Form: Each digit multiplied by its place value and added together
- Identifying Place Value: Locate the position of each digit from right to left
- Understanding Relationships: Know that each place is 10 times the next lower place
- Applying Rounding Rules: Look at the digit to the right of the target place
- Verifying Results: Check if rounded number makes sense in context
- Comparing Numbers: Start from the leftmost digit and work right
- Writing Expanded Form: Multiply each digit by its place value and add
a) 4,567
b) 82,391
c) 507,246
a) 4,567: 4=thousands, 5=hundreds, 6=tens, 7=ones
b) 82,391: 8=ten thousands, 2=thousands, 3=hundreds, 9=tens, 1=ones
c) 507,246: 5=hundred thousands, 0=ten thousands, 7=thousands, 2=hundreds, 4=tens, 6=ones
a) 3,478 to nearest ten
b) 15,624 to nearest hundred
c) 87,392 to nearest thousand
a) 3,478 to nearest ten: 8 ≥ 5, so round up → 3,480
b) 15,624 to nearest hundred: 2 < 5, so round down → 15,600
c) 87,392 to nearest thousand: 3 < 5, so round down → 87,000
a) Write 45,672 in expanded form
b) Compare: 34,567 ___ 34,657
c) Round 98,765 to nearest ten, hundred, and thousand
a) 45,672 = 40,000 + 5,000 + 600 + 70 + 2
b) 34,567 < 34,657 (same in ten thousands and thousands, then 5 < 6 in hundreds)
c) Nearest ten: 98,770, Nearest hundred: 98,800, Nearest thousand: 99,000
- It is a 5-digit number
- The digit in the thousands place is 7
- The digit in the tens place is 4
- The digit in the ones place is 9
- The digit in the hundreds place is 2
- The digit in the ten thousands place is 3
What is the number? Round it to the nearest hundred.
Build the number from the given information:
Ten Thousands: 3, Thousands: 7, Hundreds: 2, Tens: 4, Ones: 9
The number is 37,249
Rounding to nearest hundred: Target is hundreds place (2), deciding digit is tens place (4)
Since 4 < 5, round down → 37,200
The number is 37,249, rounded to the nearest hundred is 37,200
a) The largest possible number
b) The smallest possible number
c) Round both to the nearest thousand
a) Largest number: Arrange digits in descending order → 98,521
b) Smallest number: Arrange digits in ascending order → 12,589
c) Rounding:
98,521 to nearest thousand: Target is thousands place (8), deciding digit is hundreds place (5)
Since 5 ≥ 5, round up → 99,000
12,589 to nearest thousand: Target is thousands place (2), deciding digit is hundreds place (5)
Since 5 ≥ 5, round up → 13,000
a) 98,521, b) 12,589, c) 99,000 and 13,000
To round 45,678 to the nearest hundred:
Target place: Hundreds place (6)
Deciding digit: Tens place (7)
Since 7 ≥ 5, we round UP: 6 + 1 = 7
Change all digits to the right to zero: 45,700
Sarah said 45,600, which is incorrect because she rounded DOWN instead of UP.
No, Sarah is incorrect. 45,678 rounded to the nearest hundred is 45,700, not 45,600.
All numbers have 5 in ten thousands and 6 in thousands, so compare hundreds place:
56,789 and 56,798 have 7 in hundreds
56,879 and 56,897 have 8 in hundreds
So far: 56,879 and 56,897 are greater than 56,789 and 56,798
Between 56,879 and 56,897: 7 < 9 in tens, so 56,897 > 56,879
Between 56,789 and 56,798: 8 < 9 in tens, so 56,798 > 56,789
Order from greatest to least: 56,897, 56,879, 56,798, 56,789
56,897, 56,879, 56,798, 56,789