Number Theory

Lesson

Think about your times tables. Multiples are what you get after multiplying a number by an integer (a whole number). For example, in the $4$4 times tables we work our way through starting at

$4\times1=4$4×1=4

$4\times2=8$4×2=8

$4\times3=12$4×3=12 and so on.

So, the first five multiples of $4$4 are $4$4, $8$8, $12$12, $16$16 and $20$20.

We could also think of it as if we were jumping up on a number line.

So:

- The first three multiples of $2$2 are $2$2, $4$4, and $6$6.
- The first three multiples of $3$3 are $3$3, $6$6 and $9$9.
- The lowest common multiple (LCM) is $6$6.

Write down the first 5 multiples of $3$3.

No. Multiple 1st $\editable{}$ 2nd $\editable{}$ 3rd $\editable{}$ 4th $\editable{}$ 5th $\editable{}$

Question 2

What multiple of 8 is 72?

$72$72 is the $\editable{}$th multiple of $8$8.

Find the lowest common multiple of $12$12 and $20$20.

Lowest common multiple = $\editable{}$