Write the first five multiples of $21$.

Special Number 'zero'

• Write multiples of $\text{'}0\text{'}$ (zero)?
• Do you think $1$ is a multiple of zero?
• How many multiples does $\text{'}0\text{'}$ have?

Every even number greater than $4$ can be expressed as the sum of two prime numbers.

For example: $6=3+3, 8=5+3, 10=7+3=5+5$

$12=5+7, 14=11+3=7+7$

Can you further express $18, 20, 22, 24, 26, 28$ as the sum of two prime numbers?