Teacher Guide: Place Value & Rounding

🎯 Learning Objective 10-15 min lesson

Students will: Understand place value through ten thousands, read and write numbers in multiple forms, compare numbers using place value reasoning, and round numbers to the nearest 10 or 100 using number lines and place value understanding.

Key Understanding: Each place is 10 times the value of the place to its right. 1 thousand = 10 hundreds = 100 tens = 1,000 ones.

Important: No Rounding Tricks!

Per Florida B.E.S.T. guidance, do NOT use mnemonic devices like "5 or more, let it soar" or rounding rhymes. These bypass conceptual understanding. Instead, use number lines and place value reasoning to show which benchmark the number is closer to.

📦 Materials Needed

Base-ten blocks (thousands cubes, hundreds flats, tens rods, ones cubes)
Place value charts
Number lines (showing intervals of 10, 100, or 1,000)
Student worksheets

⚠️ Common Misconceptions to Address

Misconception #1: Digits Exist Independently

Students see 4,726 as "four, seven, two, six" rather than understanding each digit represents a different value based on its position.

How to Address:

Use base-ten blocks to physically show that the 7 in 4,726 represents 700 (seven hundred blocks), not 7. Write expanded form: 4,000 + 700 + 20 + 6.

Misconception #2: Always Round Up at 5

Students memorize "5 rounds up" without understanding WHY or being able to use number lines to verify.

How to Address:

Use number lines! For 45 rounding to nearest 10: draw a number line from 40 to 50, mark 45 in the middle. "Is 45 closer to 40 or 50? It's exactly in the middle, so we round up by convention."

Misconception #3: Rounding Changes the Wrong Digit

When rounding 567 to the nearest 100, students write 570 (changed the tens) instead of 600.

How to Address:

Emphasize: "What place are we rounding TO?" Circle that digit. Then ask: "What are the benchmarks (multiples of 100)?" For 567, benchmarks are 500 and 600. Which is closer?

📝 Lesson Steps

Review Place Value Structure (3 min)

Build a number with base-ten blocks. Show: 2,345 = 2 thousands + 3 hundreds + 4 tens + 5 ones.

SAY THIS:

"Each place is worth 10 times more than the place to its right. If I trade 1 thousand cube for hundreds, how many do I get? 10! That's why 2,000 = 20 hundreds."

Write Numbers in Different Forms (3 min)

Show 3,508 in three forms:

Standard form: 3,508
Expanded form: 3,000 + 500 + 8 (note: no tens!)
Word form: three thousand, five hundred eight

Compare Numbers Using Place Value (3 min)

Compare 4,829 and 4,892. Start from the left:

Thousands: Both have 4 thousands - equal so far
Hundreds: Both have 8 hundreds - still equal
Tens: 2 tens vs 9 tens - 9 > 2!

So 4,892 > 4,829.

Teach Rounding with Number Lines (4 min)

Round 274 to the nearest 100.

SAY THIS:

"What hundreds is 274 between? 200 and 300. Let me draw a number line. Where does 274 fall? It's closer to 300! So 274 rounds to 300."

Try rounding 274 to the nearest 10: between 270 and 280. It's closer to 270!

Independent Practice

Distribute worksheets. Encourage students to draw number lines for rounding problems and write expanded form for place value questions.

💻 IXL Skills to Assign After This Lesson

Recommended IXL Practice:

Place value models Write numbers in expanded form Word form to standard form Compare numbers up to 10,000 Round to the nearest 10 Round to the nearest 100 Number lines and place value

🏠 Differentiation

For struggling students: Work with 3-digit numbers first. Use physical base-ten blocks throughout. For rounding, always draw the number line.

For advanced students: Extend to 5-digit numbers. Challenge with flexible decomposition (e.g., 3,456 = 34 hundreds + 56 ones).

For home: Practice reading prices at stores, odometer readings in cars, and populations on maps.