Submarine maths quest: multiplication
A story-led junior maths adventure using depths, pressure and hidden coordinates to use equal groups, arrays and repeated patterns.
Quick answer
You can use multiplication to help a submarine navigate through deep ocean waters by counting equal groups of objects, using arrays to show patterns, and solving problems about pressure and depth.
Learning outcome
By the end of this page, you will be able to use multiplication to solve problems about equal groups, arrays, and repeated patterns in a submarine adventure.
- You can count equal groups of objects and write them as multiplication sentences
- You can use arrays to show how things are arranged in rows and columns
- You can solve simple problems using multiplication in a real ocean adventure
- You can find missing numbers in multiplication problems
Why this matters
Multiplication helps you solve problems quickly when you have equal groups of things. In a submarine adventure, you might need to know how many lights are on if there are 3 rows with 4 lights in each row. Or how many fish are swimming in groups of 5 if there are 6 groups. This is like counting by 5s six times. You'll use multiplication to help your submarine navigate, find treasure, and stay safe underwater!
How it works
Let's imagine you are on a submarine diving deeper and deeper into the ocean. You need to use multiplication to help you with your adventure.
- Count equal groups: If you see 4 groups of 3 fish, you can multiply 4 × 3 to find how many fish there are in total.
- Use arrays: If you arrange 6 lights in 2 rows with 3 lights in each row, you can make an array and multiply 2 × 3 = 6.
- Solve problems: If the pressure at 10 metres is 10 units and you go down 5 more metres, you can multiply 5 × 10 to find the pressure at that depth.
Examples you can see
Let's look at some real examples from your submarine adventure:
| Example | What you see | Multiplication sentence | Answer |
|---|---|---|---|
| 1 | 5 rows of 4 lights | 5 × 4 | 20 lights |
| 2 | 3 groups of 6 fish | 3 × 6 | 18 fish |
| 3 | 2 rows of 7 buttons | 2 × 7 | 14 buttons |
| 4 | 4 groups of 5 bubbles | 4 × 5 | 20 bubbles |
Here's how to think about these examples:
- For 5 rows of 4 lights, imagine 5 groups with 4 lights in each group. 5 × 4 = 20
- For 3 groups of 6 fish, you have 3 groups with 6 fish in each group. 3 × 6 = 18
- For 2 rows of 7 buttons, you have 2 rows with 7 buttons in each row. 2 × 7 = 14
Try it as a mini adventure
Imagine you are Captain Sarah on a submarine exploring the deep ocean. You have found a treasure map that shows a secret underwater cave. To get there, you must solve multiplication puzzles!
First stop: The Light Room
- You see 3 rows of 4 lights
- How many lights are there in total?
Second stop: The Fish Tank
- You see 6 groups of 2 fish
- How many fish are there in total?
Third stop: The Pressure Room
- The pressure at 10 metres is 10 units
- You go down 4 more metres
- What is the pressure at that depth?
Fourth stop: The Bubble Cave
- You see 5 rows of 3 bubbles
- How many bubbles are there in total?
Fifth stop: The Treasure Room
- You find 7 groups of 4 treasure coins
- How many coins are there in total?
Common mistakes
- Mistake: Thinking 3 × 4 = 12, but then counting wrong when solving the problem
Why it happens: You might count the groups or items incorrectly
Fix: Use your fingers or draw a picture to check your work - Mistake: Confusing rows and columns when using arrays
Why it happens: You might mix up which direction is the row and which is the column
Fix: Remember rows go across and columns go up and down - Mistake: Forgetting to write the multiplication sentence
Why it happens: You might just count the items without writing the number sentence
Fix: Always write the multiplication sentence after counting
Parent and carer guide
Help your child by:
- Using everyday situations like setting the table with 4 plates and 4 forks each to show multiplication
- Letting them draw arrays to show their thinking
- Asking questions like "How many rows do you see?" and "How many items are in each row?"
- Practising counting in groups together, like 3s, 4s, 5s
- Noticing when they count one by one instead of using multiplication
Remember: multiplication is about equal groups, not just memorising facts. Help them see how it works!
Practice questions
- There are 5 rows of 3 buttons. How many buttons are there in total?
- There are 4 groups of 6 fish. How many fish are there in total?
- There are 2 rows of 8 lights. How many lights are there in total?
- There are 3 groups of 7 stars. How many stars are there in total?
- There are 6 rows of 4 bubbles. How many bubbles are there in total?
Answers:
- 5 × 3 = 15 buttons
- 4 × 6 = 24 fish
- 2 × 8 = 16 lights
- 3 × 7 = 21 stars
- 6 × 4 = 24 bubbles
FAQ
What is multiplication?
Multiplication is a way to quickly add equal groups together. Instead of adding 3 + 3 + 3 + 3, you can multiply 4 × 3 = 12.
Why do we use arrays in multiplication?
Arrays help us see multiplication visually. They show us how things are arranged in rows and columns, making it easier to count and understand.
How can I practice multiplication at home?
You can practice by counting things in groups, like 3 groups of 4 toys, or by drawing arrays to show your thinking.
What if I forget a multiplication fact?
You can use repeated addition, draw arrays, or count by groups to help you find the answer.
How does multiplication help in real life?
Multiplication helps us quickly count things, like how many cookies are in 5 packs of 6 cookies, or how many seats are in 4 rows of 8 seats.