IndianTechnoEra: Comparing Two-Digit Numbers

Comparing Two-Digit Numbers

Sometimes we need to know which of two numbers is greater, which is smaller, or whether the numbers are equal.

For two-digit numbers, we can use what we know about tens and ones to compare them.

Learning Objectives

• Understand how to compare two-digit numbers.
• Compare the tens digits first.
• Compare the ones digits when the tens are equal.
• Identify greater, smaller and equal numbers.
• Use comparison symbols correctly.

What Does Comparing Mean?

Comparing means looking at two numbers to find out how they are related.

One number may be greater than another, smaller than another, or equal to another.

Compare the Tens First

When comparing two two-digit numbers, first look at their tens digits.

42   and   37

42 has 4 tens.
37 has 3 tens.

Since 4 tens are greater than 3 tens:

42 > 37

When the Tens Are Equal

Sometimes both numbers have the same number of tens. In that case, compare the ones digits.

45   and   42

Both numbers have 4 tens.
45 has 5 ones.
42 has 2 ones.

45 > 42

Greater Than

When one number has a greater value than another number, we say it is greater than the other number.

56 > 43

56 is greater than 43 because 5 tens are greater than 4 tens.

Less Than

When one number has a smaller value than another number, we say it is less than the other number.

32 < 48

32 is less than 48 because 3 tens are less than 4 tens.

Equal Numbers

Sometimes two numbers have exactly the same value. We call them equal.

36 = 36

Both numbers have 3 tens and 6 ones.

How to Compare Two-Digit Numbers

1. Look at the tens digits.
2. If the tens are different, compare them.
3. If the tens are equal, compare the ones digits.
4. Decide whether the first number is greater, smaller or equal.

Compare 64 and 68.

Both have 6 tens.
Compare the ones: 4 and 8.

64 < 68

Common Mistakes

• Comparing the ones before checking the tens.
• Looking only at the first digit without understanding its value.
• Using the greater-than symbol in the wrong direction.
• Forgetting to compare the ones when the tens are equal.

Practice

1. Compare: 45 ___ 32

2. Compare: 27 ___ 29

3. Compare: 51 ___ 51

4. Which is greater: 63 or 58?

5. Which is smaller: 42 or 47?

Try It Yourself

Write any two two-digit numbers. First compare their tens. If the tens are the same, compare their ones.

Example: 72   and   76
72 < 76

Quick Revision

• Compare tens first.
• If the tens are equal, compare ones.
• > means greater than.
• < means less than.
• = means equal to.

What Comes Next?

Once you can compare two-digit numbers, you can arrange several numbers from smallest to largest or largest to smallest.