Place Value With Decimals
Part of the Math for Young Minds curriculum — designed for neurodivergent students, grounded in real-world examples.
📋 Session plan (for teachers)
Session 1 — Place value with decimals
Grade 5 · Math for Young Minds Total time: ~25 minutes Common Core: 5.NBT.A.3 Today's idea: Every place to the right is one-tenth as much as the place before it.
What students will be able to do
By the end of this session, the student can:
- Read and write decimals out to the thousandths place.
- Explain that each place is 1/10 of the place to its left.
- Compare two decimals using place value.
Materials
- Place-value chart (one per pair) — columns from thousands down to thousandths
- Worksheet (one per student)
- Pencil
Substitution: If you don't have a printed chart, draw one on the board with these headers: thousands · hundreds · tens · ones · . · tenths · hundredths · thousandths. Students can copy it onto scratch paper.
New words
| Word | Meaning we use in class |
|---|---|
| thousandths | The third digit after the decimal point — one piece out of 1,000. |
| one-tenth as much | Each place to the right is 10× smaller than the place before it. |
Heads-up — common confusions
- Some students will say
0.45 > 0.5because 45 looks bigger than 5. Pause and line them up by place. - Tenths and hundredths get mixed up. Point to the chart every time.
0.7and0.70are the same number. Say this out loud more than once.
Plan
1 · Hello & today's idea — 2 min
"Today we're working with decimals — the numbers grown-ups actually use. Prices. Race times. Rainfall. We're going to read them, write them, and figure out which is bigger."
Hold up the place-value chart.
"This chart goes from thousands all the way down to thousandths. Every step to the right, the number gets ten times smaller."
Point across the chart, left to right, as you say it.
2 · Hands-on explore — 7 min
Hand each pair a place-value chart.
Prompt: "Write the digits of 2.345 in the chart — one digit per column. Then tell your partner what each digit is worth."
Let them work for 2 minutes. Walk around. Listen for:
- Are they putting the
2in the ones column? - Do they know
5is in the thousandths column? - Are they saying "five thousandths" out loud?
Then ask the whole group:
"What's the 3 worth? What's the 4 worth? What's the 5 worth?"
Take answers. Write them on the board:
2.345
2 ones · 3 tenths · 4 hundredths · 5 thousandths
Now the big idea:
"Look at tenths, then hundredths, then thousandths. Each one is one-tenth as much as the one before it. Ten hundredths make one tenth. Ten thousandths make one hundredth."
3 · Connect to the math — 4 min
Write on the board:
tens · ones . tenths · hundredths · thousandths
↓ ↓ ↓ ↓
each place is 1/10 of the one to its left
Now the tricky one. Write 0.7 and 0.70 side by side.
"Are these the same or different?"
Take a couple of answers. Then put both into the chart:
0.7 → 7 in tenths, nothing else
0.70 → 7 in tenths, 0 in hundredths
"Same number. A zero on the end doesn't change the value. That'll matter in a minute."
4 · Practice with support — 9 min
Pass out the worksheet.
Do problem 1 together out loud.
"Write four hundred eighty-three thousandths as a decimal."
Walk through it: the word "thousandths" tells us the last digit lands in the thousandths column. So we need three digits after the point. Answer: 0.483.
Now let students try the rest on their own or with a partner. Circulate.
- Problem 2: What is the value of the 2 in
4.027? → 2 hundredths, or 0.02. If a student says "tenths," point to the chart and count over from the decimal point together. - Problem 3: Compare
0.9and0.89. Which is bigger? → 0.9. If a student picks 0.89, have them rewrite 0.9 as 0.90 and stack them. Now it's obvious. - Problem 4 (stretch): Write three decimals between
0.5and0.6. → Any answers like0.51,0.55,0.59work. If a student is stuck, suggest they think of0.5as0.50and0.6as0.60, then fill in.
5 · What we did + Try at home — 2 min
"Today you read and wrote decimals out to thousandths. You learned every place to the right is one-tenth as much. And you compared decimals by lining up the places."
Hand out the take-home:
"Find a decimal at home with more than one digit after the point. A race time. A scale reading. A rainfall number — like 1.25 inches. Bring it in and tell me what each digit is worth."
Observation rubric — what to notice in this session
Use this during the session. One observation per student is plenty.
| Where the student is | What you'd see |
|---|---|
| Developing | Mixes up tenths and hundredths. May say 0.45 > 0.5. Needs the chart to name each place. |
| Using | Reads and writes decimals to thousandths. Compares two decimals correctly using place value. Knows 0.7 = 0.70. |
| Extending | Explains in their own words that each place is 1/10 of the one before. Invents decimals between two given decimals without prompting. |
No fail state. "Developing" today is "using" next week.
What's next (Session 2)
Building on this, Session 2 — Adding & subtracting decimals uses the same place-value thinking. We line up the decimal points and add or subtract just like whole numbers. Today's idea — that each place has its own value — is what makes that work.
✏️ Worksheet (for students)
Math for Young Minds · Grade 5
Session 1 — Place value with decimals
[ Hello ] → [ Explore ] → [ Connect ] → [ Practice ← we are here ] → [ Try at home ]
Today's big idea
Each place to the right is one-tenth as much as the place on its left.
That goes for whole numbers AND decimals. Past the decimal point we get: tenths, hundredths, thousandths.
Example we did together
thousands hundreds tens ones . tenths hundredths thousandths
— — — 3 . 1 4 2
Read it: "three and one hundred forty-two thousandths"
Write it: 3.142
Each step right is 10× smaller. Each step left is 10× bigger.
1 → 0.1 → 0.01 → 0.001
(÷10) (÷10) (÷10)
Problem 1 — together
Write four hundred eighty-three thousandths as a decimal.
Fill in the chart, then write the number:
┌─────────────────────────────────────────────────────────┐
│ ones . tenths hundredths thousandths │
│ ____ . _____ _________ __________ │
│ │
│ │
│ Decimal: 0. ____ ____ ____ │
│ │
│ │
│ Say it out loud: │
│ "______________________________________________" │
│ │
└─────────────────────────────────────────────────────────┘
Problem 2 — on your own
What is the value of the 2 in 4.027?
Build the chart and circle the 2:
┌─────────────────────────────────────────────────────────┐
│ ones . tenths hundredths thousandths │
│ ____ . _____ _________ __________ │
│ │
│ │
│ The 2 is in the ________________ place. │
│ │
│ │
│ Its value is ____________ (also written 0.____) │
│ │
└─────────────────────────────────────────────────────────┘
Problem 3 — on your own
Compare: 0.9 and 0.89. Which is bigger?
Careful — more digits doesn't mean bigger!
Line them up by place value:
┌─────────────────────────────────────────────────────────┐
│ ones . tenths hundredths │
│ 0.9 → ____ . _____ _________ │
│ 0.89 → ____ . _____ _________ │
│ │
│ │
│ Hint: rewrite 0.9 as 0.____ so they match. │
│ │
│ │
│ The bigger number is ________ │
│ │
└─────────────────────────────────────────────────────────┘
Answer in a sentence:
____________ is bigger because ____________________________.
Problem 4 — stretch
Write three decimals that are between 0.5 and 0.6.
0.5 < _______ < _______ < _______ < 0.6
Use the chart to test your answers:
┌─────────────────────────────────────────────────────────┐
│ ones . tenths hundredths thousandths │
│ ____ . _____ _________ __________ │
│ ____ . _____ _________ __________ │
│ ____ . _____ _________ __________ │
│ │
│ │
│ Could you find a decimal that uses THOUSANDTHS too? │
│ Try one: 0. ____ ____ ____ │
│ │
└─────────────────────────────────────────────────────────┘
Reminder: 0.7 and 0.70 are the same number — extra zeros at the end don't change the value.
Today's words
| Word | What it means |
|---|---|
| thousandths | The third digit after the decimal point (out of 1,000) |
| one-tenth as much | Each place to the right is 10× smaller |
Try at home tonight (1 minute)
Find a decimal at home with more than one digit after the point. Write it down and name each place value.
Where to look:
- A track-and-field or swim race time (like 12.47 seconds)
- A precise scale reading (your weight, or food on a kitchen scale)
- A long bill total (like $24.36)
- Rainfall on a weather app (like 1.25 inches)
- A measuring cup or ruler in millimeters
- A sports stat (batting average like 0.312)
My decimal: __________________________
ones . tenths hundredths thousandths
____ . _____ _________ __________
Show a grown-up tomorrow morning.
Next time: Session 2 — we'll add and subtract decimals by lining up the decimal points.
🏠 Family guide (for parents)
Math for Young Minds · Grade 5 · Session 1
A note for grown-ups: today we worked with decimals and place value
What your child did today
In class today, we looked at a place-value chart that stretches from the thousands all the way down to the thousandths.
The big idea: each place to the right is one-tenth as much as the place to its left. Ten ones make a ten. Ten tenths make a one. Ten hundredths make a tenth. The pattern keeps going.
We read and wrote decimals like 0.483, figured out what each digit is actually worth, and compared decimals like 0.9 and 0.89 by lining up the place values.
Why this matters
This is where math starts to look like the math grown-ups actually use — race times, rainfall, scale readings, money. Decimals aren't a new kind of number. They're the same place-value system, extended to the right. Getting comfortable here makes adding, subtracting, and comparing decimals feel obvious later. Understanding first. Speed comes later, on its own.
🏠 Try this tonight (1 minute)
Find one decimal somewhere at home that has more than one digit after the point. Read it together. Then ask your child to name the place value of each digit after the decimal.
Easy places to look:
| Where | Example |
|---|---|
| Weather app | 1.25 inches of rain |
| A receipt or bill total | $12.34 |
| A kitchen or bathroom scale | 4.6 lb |
| A race or stopwatch time | 10.85 seconds |
| A measuring tape (metric) | 1.75 meters |
A short script:
- "What digit is in the tenths place?"
- "What digit is in the hundredths place?"
- "So what is that 4 actually worth?" (Four hundredths, or 0.04.)
That's it. One number. One minute.
Words your child is learning
- Thousandths — the third digit after the decimal point. One out of 1,000.
- One-tenth as much — each place to the right is 10 times smaller than the place to its left.
If your child says…
"This is easy." Good. Try this: which is bigger,
0.9or0.89? Many kids say0.89because it has more digits. It's actually0.9(the same as0.90). If they get it, ask them to explain why — that's where the real understanding shows.
"This is hard." Also good. Slow down and draw a tiny place-value chart on paper: ones, decimal point, tenths, hundredths, thousandths. Write the number with one digit in each box. Once the digits have a home, the meaning gets easier. We're not in a rush.
"I don't want to." Fair. Keep it to one number. Point at the weather or a receipt, ask one question, and move on. These small noticings add up more than a long sit-down ever could.
What's next
In our next session, we'll start adding and subtracting decimals. The trick is simple: line up the decimal points, then add or subtract like whole numbers. Today's place-value work is what makes that click.
Thanks for taking a minute tonight. These small kitchen-table moments are where math lives.
— Math for Young Minds
🔑 Cheat sheet (visual)
🔢 Each place is 10× smaller
Picture 1 — The place-value chart
thousands hundreds tens ones • tenths hundredths thousandths
1000 100 10 1 1/10 1/100 1/1000
┌─────────────────────────────────────────────────────────┐
│ 3 0 5 2 • 4 8 3 │
└─────────────────────────────────────────────────────────┘
↑
decimal point
Each step → is one-tenth as much. ← Each step is 10× bigger.
Picture 2 — Read this decimal
0 • 4 8 3
↑ ↑ ↑
tenths hundr. thousandths
4/10 8/100 3/1000
Say it: "four hundred eighty-three thousandths" =
0.483
Picture 3 — What is the 2 worth?
4 • 0 2 7
↑ ↑ ↑ ↑
ones tenths ↑ thousandths
hundredths
= 0.02
➤ The 2 in 4.027 = 2 hundredths = 0.02
How to compare: line up the point!
0.9 0 ← add a 0 to match places
0.8 9
───────
↑ ↑
tenths hundredths
9 tenths > 8 tenths → 0.9 > 0.89
✨ 0.7 = 0.70 = 0.700 — extra zeros on the right don't change the value.
When is one decimal bigger? ✅ / ❌
| ✅ Compare place by place | ❌ Compare by digit count |
|---|---|
0.9 vs 0.89 → line up: 0.90 > 0.89 |
"0.89 has more digits, so it's bigger" 🚫 |
0.5 vs 0.45 → 0.50 > 0.45 |
"Longer = bigger" 🚫 |
Start at the tenths. If tied, go to hundredths. Then thousandths.
Try this in your head
Name THREE decimals between 0.5 and 0.6
0.5 ••••••••• 0.6
↑ ↑ ↑
? ? ?
➤ ____ , ____ , ____
Answer:
0.51,0.55,0.59(any three with tenths = 5 and hundredths 1–9)