4th Grade Math (Common Core) • Number and Operations—Fractions

Compare Two Decimals to Hundredths

Learn how to look at two decimal numbers and figure out which one is bigger, smaller, or if they are equal!

Friendly shapes with counting blocks and a calculator for elementary math
Inside this lesson 10 sections 5 questions 7 figures

Section 1

Where Did Decimals Come From?

Have you ever seen a price tag that says $3.49 or a stopwatch that reads 12.75 seconds? Those little dots and extra digits are called decimals. People did not always write numbers this way. For a very long time, fractions were the only tool people had for showing parts of a whole. Let's take a quick trip through history to see how decimals were invented!

Around 3000 BC • Ancient Egypt

The ancient Egyptians used fractions to divide bread and land. They wrote fractions with a special eye symbol on top. But they had no way to write decimals like we do.

Around 500 AD • China & the Middle East

Mathematicians in China and the Middle East started using a "place value" system. This means the position of a digit tells you its value. This was a big first step toward decimals!

1585 • Simon Stevin

A Dutch mathematician named Simon Stevin wrote a tiny book called De Thiende ("The Tenth"). He showed people that you could write parts of a number using tenths, hundredths, and thousandths — just by putting a dot between the whole part and the fractional part.

1600s • The Decimal Point Spreads

Over the next hundred years, scientists, merchants, and teachers all over Europe began to use decimal points. It made adding money, measuring length, and doing science much easier.

Today

Decimals are everywhere! We see them on receipts, scoreboards, thermometers, and calculators. Comparing decimals helps us answer everyday questions like "Which item costs less?" or "Who ran faster?"

So why do we need to compare decimals? Imagine you are at a store and one toy costs $4.59 and another costs $4.52. Which one is cheaper? To answer that, you need to know how to look at two decimals and decide which is greater, which is less, or if they are equal. That is exactly what this lesson is all about!

Section 2

Core Principles — The Big Ideas

Before we start comparing, let's review four important ideas that will help everything make sense.

1

Place Value Is King

In a decimal like 0.73, the 7 is in the tenths place and the 3 is in the hundredths place. The tenths place is worth more than the hundredths place, just like a dime is worth more than a penny.
2

Compare Left to Right

Always start comparing from the leftmost digit. Check the ones place first, then the tenths place, then the hundredths place. As soon as one digit is bigger, you know which decimal is greater!
3

Trailing Zeros Don't Change the Value

The decimal 0.5 is the same as 0.50. Adding a zero at the end of a decimal does not change how much it is worth. This trick helps when one decimal has more digits than the other.
4

Use Symbols: >, <, =

We use three special symbols to show the result of a comparison. The symbol > means "greater than," < means "less than," and = means "equal to." The open mouth of > or < always faces the bigger number!
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Key Takeaway

Think of comparing decimals like comparing two friends' heights. You start at the top (the biggest place value) and work your way down. If one friend is already taller at the shoulders, you don't need to look at their shoes! The same idea works with decimals: start at the left and move right until you find a difference.

Section 3

See It! — Hundredths Grids

One of the best ways to understand decimals is to draw them. A hundredths grid is a square split into 100 tiny boxes. Each small box stands for one hundredth (0.01). When you shade boxes, you can see how big a decimal really is. Let's look at two decimals side by side: 0.47 and 0.63.

0.470.6347 squares shaded63 squares shaded<
Two hundredths grids side by side. The grid on the left shows 0.47 (47 squares shaded). The grid on the right shows 0.63 (63 squares shaded). You can clearly see that 0.63 fills more of the grid, so 0.47 < 0.63.

When you look at the picture, it is easy to see that 0.63 fills up more of its grid than 0.47. More shaded squares means a bigger number. That is what comparing decimals is all about: figuring out which amount is greater. You don't always need to draw a grid, but it's a great tool when you are first learning!

Section 4

How It Works — Step by Step

Here is a simple method you can use every time you compare two decimals. Follow these three steps, and you will always get the right answer.

THE 3-STEP METHOD

Step1→LineupthedecimalpointsStep2→Comparedigitbydigit,lefttorightStep3→Write>,<,or=Step 1 → Line up the decimal points Step 2 → Compare digit by digit, left to right Step 3 → Write >, <, or =

Step 1: Line Up the Decimal Points

Write the two numbers on top of each other so that the decimal points are in a straight line. If one number has fewer digits after the decimal point, add a zero at the end to make them the same length. Remember, adding a zero after the last decimal digit does not change the number's value. For example, 0.3 becomes 0.30.

Step 2: Compare Digit by Digit, Left to Right

Start at the ones place (the digit before the decimal point). If those digits are the same, move to the tenths place. If those are the same too, move to the hundredths place. As soon as you find a place where the digits are different, the number with the bigger digit in that place is the greater number.

Step 3: Write the Symbol

Use > (greater than), < (less than), or = (equal to) between the two decimals. A fun trick: the open side of the > or < symbol always points toward the bigger number, like a little mouth that wants to eat the larger amount!

PLACE VALUE REMINDER

ones.tenthshundredths3.47ones . tenths hundredths 3 . 4 7

In the number 3.47, the 3 is in the ones place, the 4 is in the tenths place, and the 7 is in the hundredths place.

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Key Takeaway

Think of comparing decimals like comparing two addresses on the same street. First you check the house number (ones place). If they live on the same block, then you check which house is farther down (tenths). If even those are the same, you look at the apartment number (hundredths). The first difference you find tells you who lives "farther up" the number line!

Section 5

The Number Line — Another Way to See It

A number line is a straight line with numbers placed in order from least to greatest. When you place decimals on a number line, the one farther to the right is always greater. Let's look at where some decimals land between 0 and 1.

0.00.51.00.250.400.520.78← LESSGREATER →
A number line from 0 to 1 showing 0.25, 0.40, 0.52, and 0.78. Numbers farther to the right are greater.

Look at the number line above. The decimal 0.25 is closest to zero, so it is the smallest. The decimal 0.78 is farthest to the right, so it is the greatest. We can write: 0.25 < 0.40 < 0.52 < 0.78. Any time you place two decimals on a number line, the one on the right is always the bigger one.

DecimalOnesTenthsHundredthsTotal Hundredths
0.2502525
0.4004040
0.5205252
0.7807878

Here's a handy shortcut: you can think of each decimal to the hundredths as a whole number of hundredths. The decimal 0.25 means 25 hundredths, and 0.78 means 78 hundredths. Since 25 < 78, you know right away that 0.25 < 0.78. This trick works great because comparing whole numbers is something you already know how to do!

Section 6

Worked Example

Let's walk through a full problem together. We will compare 0.8 and 0.76.

Comparing 0.8 and 0.76

  1. 1

    Step 1 — Line Up & Add a Zero

    Write the numbers stacked on top of each other. The first number, 0.8, only has one digit after the decimal. So we add a zero to make it 0.80. Now both numbers go to the hundredths place.
    0.80 and 0.76
  2. 2

    Step 2 — Compare the Ones Place

    Both numbers have a 0 in the ones place. They match! So we move to the next place.
  3. 3

    Step 3 — Compare the Tenths Place

    In 0.80, the tenths digit is 8. In 0.76, the tenths digit is 7. Since 8 is greater than 7, we already have our answer! We don't even need to look at the hundredths.
  4. 4

    Step 4 — Write the Answer

    Since 8 tenths is more than 7 tenths:
    0.8 > 0.76

Did you notice something? Even though 0.76 has more digits, it is actually the smaller number! This is a very common trick question. The number of digits does not tell you which decimal is bigger — place value is what matters.

Section 7

Tips, Traps & Common Mistakes

When students first learn to compare decimals, there are a few mistakes that pop up a lot. Let's go over them so you can avoid them.

Common TrapWhy It's WrongHow to Fix It
"More digits = bigger number"0.9 has one decimal digit but 0.62 has two. Students sometimes think 0.62 is bigger. But 0.9 = 0.90, which is bigger than 0.62.Always add trailing zeros so both decimals have the same number of digits, then compare.
Ignoring the ones placeComparing 2.35 and 1.99 — some students jump straight to the tenths and see that 9 > 3. But 2 ones beats 1 one!Always start comparing from the leftmost digit (the ones place).
Flipping the > and < symbolsStudents sometimes write 0.47 > 0.63 by accident.Remember: the open mouth of the symbol always faces the bigger number. Or think of it as a hungry alligator that eats the larger meal!
Thinking 0.30 is more than 0.3These are the exact same number! Adding a zero to the end does not change the value.0.30 = 0.3. Use trailing zeros as a tool, not a trick.
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Key Takeaway

Here's a trick to never mix up > and <: imagine the symbol is a little alligator mouth. The alligator is always hungry and wants to eat the bigger number. So the wide-open side points to the larger decimal. If you write 0.63 > 0.47, the alligator is opening its mouth toward 0.63 because that's the bigger meal!

Section 8

What's Next? — Building on This Skill

Comparing decimals to the hundredths is a skill you will use over and over again. Here's a peek at what comes next as you move through math.

What You Know NowWhat You'll Learn Next
Compare two decimals to the hundredths placeCompare and order decimals to the thousandths place (e.g., 0.345 vs. 0.349)
Use >, <, and = with two decimalsPut a whole list of decimals in order from least to greatest
Use grids and number lines to picture decimalsAdd and subtract decimals using place value
Understand tenths and hundredthsConnect decimals to fractions (like 0.75 = ¾) and percentages (75%)

In 5th grade, you will compare decimals that go even further — to the thousandths place. But the method is exactly the same! You still line up the decimal points, compare left to right, and use the same symbols. So the work you are doing right now is building a strong foundation for everything ahead.

You will also start to see that decimals, fractions, and percentages are just three different ways to write the same number. For example, the decimal 0.50 is the same as the fraction ½ and the percentage 50%. Cool, right?

Section 9

Practice Problems

Time to try it yourself! Work through each problem, then click "Show Answer" to check your work. Don't peek too early — the best learning happens when you try first!

Question 1: Problem 1 — Conceptual

In the decimal 0.86, which digit is in the tenths place and which is in the hundredths place? Why does the tenths digit matter more when comparing?
Show answer
The 8 is in the tenths place and the 6 is in the hundredths place. The tenths digit matters more because one tenth is the same as ten hundredths. Think of it like money: a dime (one tenth of a dollar) is worth more than a penny (one hundredth of a dollar). So the tenths place always beats the hundredths place when you compare! Great job if you got this!

Question 2: Problem 2 — Basic

Compare 0.34 and 0.29. Write >, <, or = between them.
Show answer
Both numbers have 0 in the ones place, so we go to the tenths. The first number has 3 tenths and the second has 2 tenths. Since 3 > 2, we already know the answer: 0.34 > 0.29. We didn't even need to look at the hundredths place. The tenths told us everything!

Question 3: Problem 3 — Intermediate

Compare 0.7 and 0.65. Be careful — the numbers have a different number of digits!
Show answer
First, add a trailing zero to 0.7 so it becomes 0.70. Now compare 0.70 and 0.65. The ones are both 0. The tenths: 7 vs. 6. Since 7 > 6, 0.7 > 0.65. Even though 0.65 has more digits, it's the smaller number. Remember: more digits does not always mean a bigger value!

Question 4: Problem 4 — Applied

Maya ran the 50-meter dash in 8.54 seconds. Her friend Zara finished in 8.59 seconds. Who ran faster? (Hint: in a race, the smaller time wins!)
Show answer
Compare 8.54 and 8.59. The ones are both 8. The tenths are both 5. Now look at the hundredths: 4 vs. 9. Since 4 < 9, we know that 8.54 < 8.59. A smaller time means a faster run, so Maya ran faster! She beat Zara by 5 hundredths of a second. That's super close!

Question 5: Problem 5 — Challenge

Put these four decimals in order from least to greatest: 0.41, 0.14, 0.40, 0.09.
Show answer
Think of each decimal as a number of hundredths: 0.41 = 41 hundredths, 0.14 = 14 hundredths, 0.40 = 40 hundredths, 0.09 = 9 hundredths. Now sort the whole numbers: 9, 14, 40, 41. So the order from least to greatest is: 0.09 < 0.14 < 0.40 < 0.41. Notice that 0.40 and 0.41 are very close — they only differ in the hundredths place! Awesome work if you got all four in the right spot!

Summary

Lesson Summary

Summary

In this lesson, you learned how to compare two decimals that go up to the hundredths place. The key to comparing decimals is understanding place value: the ones place is worth the most, followed by the tenths, and then the hundredths. You always compare left to right, one place at a time, until you find a difference. If one decimal has fewer digits, you can add a trailing zero without changing its value.

You practiced using the symbols > (greater than), < (less than), and = (equal to) to show your answer. You saw how hundredths grids and number lines make decimals easy to picture. And you learned to watch out for common traps, like thinking that more digits always means a bigger number. Remember: the alligator mouth always opens toward the bigger number! With these tools, you are ready to compare any two decimals with confidence.

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