Number patterns
🎯 In this topic you will
- Recognise and use odd and even numbers up to 20
- Count forwards and backwards in ones, twos, and tens from any number up to 20
🧠 Key Words
- counting back
- counting on
Show Definitions
- counting back: Finding a smaller number by moving backwards in steps from a starting number.
- counting on: Finding a larger number by moving forwards in steps from a starting number.
🔢 Patterns in Numbers
There are many different patterns in numbers. Some patterns are made by counting in twos or tens. Some patterns are so well known that they have their own names, such as odd numbers and even numbers.
❓ EXERCISES
1. In Unit $1$, you coloured even numbers red and odd numbers blue. Continue the pattern to $20$.
👀 Show answer
Odd numbers to be coloured blue: $11, 13, 15, 17, 19$.
2. Sort each number into the correct circle.
👀 Show answer
Even numbers: $12,\ 8,\ 6,\ 18$
🧠 Think like a Mathematician
Jamal said, ‘There are $4$ odd numbers between $3$ and $13$. I wonder if there will always be $4$ odd numbers between a number and the number that is ten more.’
What do you think?
Work on your own to investigate whether this is always true.
Show Answers
- Answer: Yes, there will always be $4$ odd numbers between any number and the number that is ten more. In every group of ten consecutive numbers, the numbers alternate odd and even, so exactly half are odd. Between the two end numbers (not counting the endpoints), there are $10 - 1 = 9$ numbers, and exactly $4$ of them are odd.
❓ EXERCISES
3. Mr Even always puts an even number of socks on his washing line. He washes $17$ socks. Will he put them all on the washing line? How do you know?
👀 Show answer
4. Count in twos to find out how many pencils.
👀 Show answer
5. Bicycles have $2$ wheels. A bicycle maker has $14$ wheels. How many bicycles can she make?
👀 Show answer
❓ EXERCISES
6. Write the missing numbers. Draw a ring around the correct word to complete this sentence: When I count in twos from zero I say odd / even numbers.
👀 Show answer
Row $2$: $2$ fewer than $16$ is $14$; $2$ more than $16$ is $18$.
Row $3$: The middle number is $6$ because $2$ more than $4$ is $6$; $2$ more than $6$ is $8$.
Counting in twos from zero gives even numbers.
7. Lily wanted to find out how many wheels are on $9$ bicycles. She drew some jumps of $2$. How many wheels are there? Draw Lily’s jumps.
👀 Show answer
8. Write the missing numbers.
👀 Show answer
Row $2$: The middle number is $18$ because $10$ fewer than $18$ is $8$; $10$ more than $7$ is $17$.
🔍 Exploring Jumps on a Number Line
Look at the number line and the number track. They both show $10$ fewer and $10$ more.
