Lesson Plan
Decimal Dash
Students will be able to represent decimals to the tenths and hundredths visually and relate them to fractions with denominators of 10 and 100. Students will also be able to place decimals on a number line.
Understanding decimals is a fundamental skill that students will use throughout their lives, from counting money to understanding measurements. This lesson helps build a strong foundation by connecting decimals to concepts they already know, like fractions and whole numbers.
Audience
4th Grade Students
Time
30 minutes
Approach
Hands-on activities, visual aids, and group discussions.
Materials
Whiteboard or projector, Markers or pens, Decimal Dash Slides, Decimal Explorer Worksheet, and Base ten blocks (optional)
Prep
Prepare Materials
10 minutes
- Review the Decimal Dash Lesson Plan and all generated materials.
- Prepare the whiteboard or projector for the Decimal Dash Slides.
- Print copies of the Decimal Explorer Worksheet for each student or small group.
- Gather optional base ten blocks if desired for hands-on representation.
Step 1
Introduction: What's a Decimal?
5 minutes
- Begin by asking students what they know about decimals. (e.g., "Where do we see decimals in our daily lives?")
- Introduce the concept of decimals as parts of a whole, similar to fractions.
- Use Decimal Dash Slides to show examples of decimals (money, measurements).
Step 2
Decimal-Fraction Connection
10 minutes
- Display a 10x10 grid on the Decimal Dash Slides. Shade parts of the grid and ask students to express the shaded portion as a fraction and then as a decimal.
- Guide students to understand that a fraction with a denominator of 10 or 100 can be written as a decimal.
- Work through examples like 3/10 = 0.3 and 25/100 = 0.25.
Step 3
Number Line Placement
8 minutes
- Use the number line examples on the Decimal Dash Slides to show how decimals fit between whole numbers.
- Practice placing decimals like 0.5, 0.75, and 0.1 on a number line.
- Emphasize that 0.5 is the same as 5/10, and it sits exactly in the middle of 0 and 1.
Step 4
Worksheet Activity: Decimal Explorer
5 minutes
- Distribute the Decimal Explorer Worksheet.
- Have students work individually or in small groups to complete the worksheet, practicing visual representation and number line placement.
- Circulate to provide support and answer questions.
Slide Deck
Welcome to Decimal Dash!
What are decimals and why are they important?
Hello everyone! Today we're going on a 'Decimal Dash'! Has anyone heard the word 'decimal' before? Where might you have seen or heard it? (Allow for student responses, e.g., money, measurements, sports scores). Decimals are all around us, and today we're going to become decimal detectives!
Decimals: Parts of a Whole
Decimals help us show amounts that are less than a whole number.
Think about money! $0.50 is half a dollar.
Think about a dollar bill. How many quarters make a dollar? Four! And how many cents make a dollar? One hundred! A decimal is a way to show parts of a whole, just like fractions. For example, 50 cents is half a dollar, or 1/2. As a decimal, we write it as 0.50.
Fractions and Decimals: Best Friends!
Decimals are like fractions, but they use a different way to write parts of a whole.
- 1/10 = 0.1 (one tenth)
- 5/10 = 0.5 (five tenths)
- 25/100 = 0.25 (twenty-five hundredths)
- 7/100 = 0.07 (seven hundredths)
Look at the grids – how many squares are shaded?
Let's look at this grid. Imagine it's a giant chocolate bar with 100 squares. If I shade 10 squares, what fraction of the chocolate bar is shaded? (10/100). How can we write that as a decimal? (0.10 or 0.1). If I shade 3 squares, it's 3/100, or 0.03. Point out how the place value after the decimal point relates to tenths and hundredths.
Decimals on a Number Line
Decimals fit right between whole numbers!
- 0.5 is halfway between 0 and 1.
- 0.2 is closer to 0.
- 0.8 is closer to 1.
Let's practice placing some decimals on a number line!
Now, let's see where decimals live on a number line. Remember that a number line shows numbers in order. Decimals fit right between our whole numbers. If we have 0 and 1, where would 0.5 go? Exactly in the middle! It's halfway between 0 and 1. Let's try placing 0.3 and 0.9. What about 0.25? It would be between 0.2 and 0.3, a quarter of the way to 0.3. Remind students that 0.5 is equivalent to 0.50.
Your Turn: Decimal Explorer!
Complete the Decimal Explorer Worksheet to practice what you've learned.
- Shade in grids to represent decimals.
- Place decimals on a number line.
Time to put your decimal detective skills to work! I'm handing out the 'Decimal Explorer Worksheet'. You'll get to practice representing decimals visually and placing them on a number line. Work quietly or with your small groups, and I'll be around to help if you have any questions. Remember to think about our chocolate bar grids and number lines!
Decimal Discoveries!
You're now decimal explorers!
Keep practicing and looking for decimals in the world around you.
Great job today, everyone! We've explored decimals, seen how they're related to fractions, and learned to place them on a number line. Keep an eye out for decimals in your everyday life – you'll start noticing them everywhere!
Worksheet
Decimal Explorer Worksheet
Name: _____________________________
Date: _____________________________
Part 1: Shade the Decimals!
For each grid, shade the correct number of squares to represent the decimal shown. Each large square represents one whole, and each small square represents one hundredth.
-
0.3
[Grid for 0.3 - Imagine a 10x10 grid. Students will shade 3 columns or 30 squares.]
-
0.50
[Grid for 0.50 - Imagine a 10x10 grid. Students will shade 5 columns or 50 squares.]
-
0.07
[Grid for 0.07 - Imagine a 10x10 grid. Students will shade 7 individual squares.]
-
0.8
[Grid for 0.8 - Imagine a 10x10 grid. Students will shade 8 columns or 80 squares.]
Part 2: Decimal Number Lines!
Draw a point on the number line to represent each decimal. The first one is done for you.
-
0.4
0 -----X----- 1 (The 'X' is roughly at 0.4)
-
0.9
0 ----------- 1
-
0.25
0 ----------- 1
-
0.7
0 ----------- 1
Part 3: Convert it!
Write the decimal for each fraction.
-
5/10 = _________
-
60/100 = _________
-
2/10 = _________
-
15/100 = _________
Answer Key
Decimal Explorer Answer Key
Part 1: Shade the Decimals!
For each grid, shade the correct number of squares to represent the decimal shown.
-
0.3
Thought Process: 0.3 means three tenths. In a 10x10 grid, 3 tenths is equivalent to 30 hundredths. Therefore, shade 30 small squares or 3 full columns. -
0.50
Thought Process: 0.50 means fifty hundredths. In a 10x10 grid, this means 50 small squares or 5 full columns. -
0.07
Thought Process: 0.07 means seven hundredths. In a 10x10 grid, this means 7 individual small squares. -
0.8
Thought Process: 0.8 means eight tenths. In a 10x10 grid, 8 tenths is equivalent to 80 hundredths. Therefore, shade 80 small squares or 8 full columns.
Part 2: Decimal Number Lines!
Draw a point on the number line to represent each decimal.
-
0.4
Thought Process: 0.4 is less than 0.5 (halfway) but greater than 0. The point should be placed just before the halfway mark between 0 and 1.
0 --.--X---- 1 (X is at 0.4) -
0.9
Thought Process: 0.9 is very close to 1, but not quite 1. It should be placed almost at the end of the number line, just before 1.
0 --------X- 1 (X is at 0.9) -
0.25
Thought Process: 0.25 is a quarter of the way between 0 and 1. It is exactly halfway between 0.2 and 0.3. The point should be placed between 0 and 0.5, closer to 0.2.
0 -X-------- 1 (X is at 0.25) -
0.7
Thought Process: 0.7 is greater than 0.5 (halfway) but less than 1. It should be placed beyond the halfway mark, closer to 0.75.
0 ---------X 1 (X is at 0.7)