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Maths Adventures

Sailing maths quest: place value

A story-led junior maths adventure using maps, bearings and voyage planning to decode big numbers by hundreds, tens and ones.

Quick answer

By the end of this page, you will understand how place value helps you read and write big numbers by breaking them into hundreds, tens, and ones – just like reading a map to find your way to treasure!

Learning outcome

By the end of this page, you will be able to:
  • Separate any number into hundreds, tens, and ones
  • Read and write numbers up to 999 using place value
  • Use place value to solve simple addition and subtraction problems
  • Apply your knowledge to plan a sailing voyage using numbers

Why this matters

Place value is like a secret code that helps you understand how big numbers work. When you sail a ship, you need to read maps, follow directions, and count your treasures – all of which use place value! Whether you're counting how many coins are in your treasure chest, planning how many miles you'll travel, or reading a compass bearing, place value helps you make sense of numbers.

How it works

Place value means that the position of each digit in a number tells you how much it's worth. The rightmost digit is the ones place, then the next is the tens place, and the next is the hundreds place. For example, in the number 345:
  • 3 is in the hundreds place, so it means 300
  • 4 is in the tens place, so it means 40
  • 5 is in the ones place, so it means 5
When you add them together: 300 + 40 + 5 = 345.

Examples you can see

Let's imagine you're planning a sailing trip. You need to know how many miles you'll sail each day. If you sail 247 miles in one week, you can break it down like this:
Hundreds Tens Ones
2 4 7
This means 200 + 40 + 7 = 247 miles. You can also use place value to add numbers:
  • 324 + 156 = ?
  • 300 + 100 = 400
  • 20 + 50 = 70
  • 4 + 6 = 10
  • 400 + 70 + 10 = 480

Try it as a mini adventure

Adventure: Sailing to Treasure Island You are Captain Maths, and you have a treasure map! Your ship can sail 128 miles on Day 1, 256 miles on Day 2, and 317 miles on Day 3. How far have you sailed in total? Let’s break it down:
  • Day 1: 128 miles
  • Day 2: 256 miles
  • Day 3: 317 miles
Now, let’s split each number into hundreds, tens, and ones:
  • 128 = 100 + 20 + 8
  • 256 = 200 + 50 + 6
  • 317 = 300 + 10 + 7
Add the hundreds: 100 + 200 + 300 = 600 Add the tens: 20 + 50 + 10 = 80 Add the ones: 8 + 6 + 7 = 21 Total: 600 + 80 + 21 = 701 miles You sailed 701 miles in total!

Common mistakes

  • Mistake: Mixing up the place values. Why it happens: Not knowing which digit is in which place. Fix: Use a place value chart or draw circles to show hundreds, tens, and ones.
  • Mistake: Forgetting to include zero in a number. Why it happens: Thinking that a number like 305 is just 3 and 5. Fix: Always write the number in expanded form: 305 = 300 + 0 + 5.
  • Mistake: Adding digits without considering place value. Why it happens: Adding 3 + 5 + 7 in 345 + 257 as if they’re all the same size. Fix: Always add hundreds with hundreds, tens with tens, and ones with ones.

Parent and carer guide

As a parent or carer, you can help by:
  • Using everyday items like coins or blocks to show how 10 ones make 1 ten, and 10 tens make 1 hundred
  • Playing a place value game where you say a number and ask your child to show it with base-10 blocks or drawings
  • Practicing with real-life examples like counting money or measuring distances
  • Encouraging your child to read numbers aloud, breaking them into hundreds, tens, and ones
  • Not worrying if they make a mistake – it’s part of learning!

Practice questions

  1. Break down the number 467 into hundreds, tens, and ones.
  2. What is 523 + 245?
  3. Write the number that is 3 hundreds, 6 tens, and 9 ones.
  4. How many miles have you sailed if you sail 134 miles on Day 1 and 256 miles on Day 2?
  5. What is 700 + 150 + 23?
Answers:
  1. 400 + 60 + 7
  2. 768
  3. 369
  4. 390 miles
  5. 873

FAQ

What is place value?

Place value is how we know how much each digit in a number is worth based on its position. The rightmost digit is ones, the next is tens, and the next is hundreds.

Why is place value important?

Place value helps us understand big numbers and makes it easier to add, subtract, and compare numbers.

How can I practice place value at home?

You can use everyday items like coins, blocks, or even your fingers to practice grouping numbers into hundreds, tens, and ones.

What comes after hundreds in place value?

After hundreds come thousands, then ten thousands, and so on. But for now, we focus on hundreds, tens, and ones.

Can I use place value with decimals?

Yes! But for now, we’re learning with whole numbers up to 999. Decimal place value is for later, when you learn about tenths and hundredths.