Explain your reasoning.
Comparing numbers: Determining if one number is greater than (>), less than (<), or equal to (=) another number using place value.
- Compare the tens digits first
- If tens are different, the number with more tens is greater
- If tens are the same, compare the ones digits
45 has 4 tens, 37 has 3 tens
Since 4 > 3, then 45 > 37
When tens are different, the number with more tens is always greater
45 > 37 (45 is greater than 37)
45 is greater than 37 because 45 has 4 tens and 37 has 3 tens. Since 4 > 3, then 45 > 37.
• Place value comparison: Compare tens first, then ones if needed
• Greater than: When tens differ, the number with more tens is greater
• Comparison logic: 4 tens (40) is more than 3 tens (30)
Explain your reasoning.
Same tens comparison: When tens digits are equal, compare the ones digits to determine which number is greater or lesser.
63 has 6 tens, 68 has 6 tens
Since 6 = 6, move to ones digits
63 has 3 ones, 68 has 8 ones
Since 3 < 8, then 63 < 68
63 < 68 (63 is less than 68)
63 is smaller than 68 because both have 6 tens, but 63 has 3 ones while 68 has 8 ones. Since 3 < 8, then 63 < 68.
• Same tens rule: When tens are equal, compare ones digits
• Less than: When ones differ and are in the same tens group
• Comparison logic: 63 = 60 + 3, 68 = 60 + 8, since 3 < 8, then 63 < 68
Explain your reasoning.
Equal numbers: Two numbers are equal when both their tens and ones digits are the same.
Both numbers have 5 tens
Since 5 = 5, continue to ones
Both numbers have 4 ones
Since 4 = 4, the numbers are equal
54 = 54 (54 is equal to 54)
54 and 54 are equal because both have 5 tens and 4 ones. When both tens and ones digits are the same, the numbers are equal.
• Equality rule: Numbers are equal when both tens and ones digits match
• Comparison logic: 54 = 50 + 4 and 54 = 50 + 4, so they are identical
• Reflexive property: Any number is equal to itself
• Tens first: Always compare tens digits before ones digits
• Greater than: More tens means greater number
• Same tens: Compare ones digits when tens are equal
• Equal numbers: Both tens and ones digits must match
a) 28 ___ 31
b) 45 ___ 42
c) 67 ___ 67
Mixed practice: Combining different types of comparisons to strengthen understanding.
28 has 2 tens, 31 has 3 tens
Since 2 < 3, then 28 < 31
45 and 42 both have 4 tens
45 has 5 ones, 42 has 2 ones
Since 5 > 2, then 45 > 42
Both numbers have 6 tens and 7 ones
Since both digits match, 67 = 67
a) 28 < 31
b) 45 > 42
c) 67 = 67
• Consistency: Apply the same method to all parts of the problem
• Place value: Position determines the value of each digit
• Verification: Check each answer by reviewing place values
Problem solving: Applying comparison concepts to real-world scenarios with visual representations.
Sarah has 5 tens blocks and 3 ones blocks = 50 + 3 = 53
Jake has 4 tens blocks and 8 ones blocks = 40 + 8 = 48
Sarah's number (53) has 5 tens, Jake's number (48) has 4 tens
Since 5 > 4, then 53 > 48
Sarah has more blocks. Sarah has 53 blocks and Jake has 48 blocks. Since 53 > 48, Sarah has more.
• Visual representation: Blocks help understand the concept concretely
• Place value comparison: Compare tens first, then ones if needed
• Application: Connect abstract math to real-world problems
Comparing numbers: Determining if one number is greater than (>), less than (<), or equal to (=) another number.
Place value: The value of a digit based on its position in a number (tens, ones).
Tens: Groups of 10 (1 ten = 10, 2 tens = 20, etc.).
Ones: Single units (1 one = 1, 2 ones = 2, etc.).
Greater than (>): One number is larger than another.
Less than (<): One number is smaller than another.
Equal (=): Two numbers have the same value.
- Identify place values: Determine tens and ones in each number
- Compare tens first: Look at the tens digits of both numbers
- Make decision if different: If tens differ, greater tens means greater number
- Compare ones if equal: If tens are the same, compare the ones digits
- Write the comparison: Use >, <, or = symbols appropriately
• Primary rule: Always compare tens digits first
• Secondary rule: Only compare ones digits if tens are equal
• Greater than principle: More tens = greater number
• Same tens principle: Compare ones when tens are equal
• Equality principle: Both tens and ones must match for equality
Questions & Answers
Question: Why do we compare the tens first? Why not the ones?
Answer: We compare tens first because tens are more valuable than ones. Think of it like this:
- 1 ten = 10 ones, so tens are worth more
- 4 tens (40) is more than 3 tens (30), even if the ones are different
- It's like comparing bags of 10 marbles vs single marbles
For example: 41 vs 39
- 41 has 4 tens (40) and 1 one (1) = 41 total
- 39 has 3 tens (30) and 9 ones (9) = 39 total
Even though 39 has more ones (9 > 1), 41 is still greater because 4 tens (40) is more than 3 tens (30).
Question: My child is having trouble understanding the greater than (>) and less than (<) symbols. How can I help them remember which is which?
Answer: Here are some helpful memory tricks for the symbols:
- Alligator method: The alligator mouth opens toward the bigger number (the alligator wants to eat the bigger meal!)
- Arrow method: Think of the symbol as pointing to the smaller number
- Character method: > looks like a "greater" g, < looks like an "less" l
Examples:
- 5 > 3 (the alligator eats the 5 because it's bigger)
- 2 < 7 (the alligator eats the 7 because it's bigger)
Practice with real objects: place 5 blocks on one side and 3 blocks on the other, then use the alligator mouth to show which is greater.
Question: What happens when two numbers have the same tens but different ones? Like 64 and 67?
Answer: When two numbers have the same tens digit, you compare the ones digits to determine which is greater:
For 64 and 67:
- Both numbers have 6 tens (60)
- 64 has 4 ones (4)
- 67 has 7 ones (7)
- Since 4 < 7, then 64 < 67
Think of it like having the same number of bags of 10 marbles (6 bags each), but one person has 4 extra marbles and the other has 7 extra marbles. The person with 7 extra marbles has more total marbles.
Rule: When tens are equal, the number with more ones is greater.