X Tables
Maths Adventures

Mermaid maths quest: coordinates

A story-led junior maths adventure using pearl patterns, shell money and underwater symmetry to locate hidden items on grids and maps.

Quick answer

You can find any location underwater using a special system called coordinates – like a treasure map with numbers that tell you exactly where to look!

Learning outcome

By the end of this page, you will be able to use coordinates to find hidden items on a grid, just like a mermaid looking for treasures in the ocean. Success signs:
  • You can name the position of a point on a grid using coordinates
  • You can plot points on a grid using given coordinates
  • You can use a simple map with rows and columns to find a hidden item
  • You can explain how coordinates help you find your way around

Why this matters

Coordinates are like a secret code that helps you find things quickly and exactly. Whether you're looking for a treasure chest in a mermaid's underwater cave, planning where to place your LEGO blocks, or finding your seat on a football pitch, coordinates are used everywhere. In real life, GPS systems use coordinates to guide you to the right place. When you play games like Battleship or use a map to find a friend, you're using the same idea. Understanding coordinates helps you become a better explorer, builder, and problem solver.

How it works

Coordinates are two numbers that tell you exactly where something is on a grid. The first number is the horizontal position (called the x-coordinate), and the second number is the vertical position (called the y-coordinate). You always read them as (x, y). For example, if you see (3, 5), it means 3 steps to the right and 5 steps up from the bottom left corner. To use coordinates:
  1. Start at the bottom left corner of your grid – this is where (0, 0) is
  2. Move along the bottom (horizontal) to find your first number
  3. Move up (vertical) to find your second number
  4. Mark the spot where the two lines meet

Examples you can see

Imagine you're a mermaid diving in the ocean. You have a treasure map with a grid, and you need to find a pearl that's hidden at the point (4, 3). Here's how you do it:
Step Action Where you are
1st time Start at the bottom left corner (0, 0)
2nd time Move 4 steps to the right (4, 0)
3rd time Move 3 steps up (4, 3)
4th time Mark the spot Here’s your pearl!
Another example: A mermaid finds a shell that is at (2, 6). Let’s find it:
  • Start at (0, 0)
  • Move 2 steps right to (2, 0)
  • Move 6 steps up to (2, 6)
  • That’s where the shell is!
You can also use a simple treasure hunt grid with letters and numbers like this:
1 2 3 4 5
A ? ? ? ? ?
B ? ? ? ? ?
C ? ? ? ? ?
D ? ? ? ? ?
E ? ? ? ? ?
If you want to find the treasure at (3, 2), you look at row C (because 2 is the row number) and column 3 (because 3 is the column number). That's the spot!

Try it as a mini adventure

Mermaid’s Treasure Hunt You are a mermaid who has found a secret underwater cave. Inside, there are three treasures hidden at different coordinates:
  • A pearl at (1, 4)
  • A golden shell at (5, 2)
  • A silver coin at (3, 5)
Your mission is to draw a grid and mark where each treasure is. Use a grid like this:
1 2 3 4 5
1 ? ? ? ? ?
2 ? ? ? ? ?
3 ? ? ? ? ?
4 ? ? ? ? ?
5 ? ? ? ? ?
Draw a dot for each treasure and label them:
  1. Dot at (1, 4) – Pearl
  2. Dot at (5, 2) – Golden shell
  3. Dot at (3, 5) – Silver coin
Can you find the treasure at (2, 3)? Try to find it yourself!

Common mistakes

  • Mistake: Reading coordinates as (y, x) instead of (x, y)
    Why it happens: Confusing which number is horizontal and which is vertical
    Fix: Remember that x is for left and right, y is for up and down
  • Mistake: Starting from the top or the wrong corner
    Why it happens: Not remembering that coordinates start at the bottom left
    Fix: Always start at (0, 0) at the bottom left
  • Mistake: Counting the starting point as part of the steps
    Why it happens: Thinking you need to move 1 more step than you actually do
    Fix: Count steps from the starting point, not including it

Parent and carer guide

As a parent or carer, you can help your child by:
  • Playing a simple treasure hunt game using a grid and coordinates
  • Using everyday maps or floor plans to find locations (like "the fridge is at (2, 3) on this kitchen grid")
  • Practising with a grid paper and drawing dots at different coordinates
  • Encouraging your child to explain how they found a point – this helps them learn the process
  • Not worrying if they make a mistake – it’s part of learning!
If your child is stuck:
  • Ask them to start at (0, 0) and count steps
  • Reinforce that the first number is always horizontal (left to right)
  • Use a simple example like "find the point at (2, 1)"

Practice questions

  1. What are the coordinates of the point that is 3 steps right and 2 steps up?
  2. Where is the point (4, 1) located?
  3. Plot the point (0, 5) on a grid
  4. Find the treasure at (2, 3). What row and column is it in?
  5. Which point is at (5, 4)?
Answers:
  1. (3, 2)
  2. 3 steps right and 1 step up from (0, 0)
  3. Start at (0, 0), go 0 steps right and 5 steps up
  4. Row C, Column 2
  5. Row E, Column 4

FAQ

What are coordinates used for?

Coordinates help us find exact locations on a grid or map. They are used in games, maps, science, and even in space travel!

Can I use coordinates in real life?

Yes! You can use coordinates to find your seat on a train, locate items in a store, or play games like Battleship.

How do I remember which number is which?

Think of it like reading a book – you go left to right first (x), then up and down (y). You can also remember: "X is for Xylophone (horizontal), Y is for Yacht (vertical)."

Are coordinates the same as directions?

Not exactly. Directions tell you how to get somewhere, but coordinates tell you exactly where something is. For example, "go 3 steps right and 2 steps up" is a direction, while "(3, 2)" is a coordinate.

What comes after learning coordinates?

After learning coordinates, you can learn about graphs, maps, and how to plot more complex shapes or paths. It’s the start of understanding how to find and describe locations in space.