Lesson
We've already looked at how to add numbers together. Now we are going to look at multiplication, which is a special math tool we can use to quickly find the total of lots of groups of the same size.
Let's start by watching a video.
So we now know that doubling is the same as multiplying by $2$2.
We don't always have pictures to help so let's look at some ways we can think about multiplying by $2$2 without pictures with some examples.
Examples
Question 1
$2\times9$2×9
Think: This means $2$2 groups of $9$9, which we can also think of as $9+9$9+9 or double $9$9.
Do: $9+9=18$9+9=18 so $2\times9=18$2×9=18.
Question 2
$4\times2$4×2
Think: This means $2$2 groups of $4$4, which we can also think of as $4+4$4+4 or double $4$4.
Do: Double $4$4 is $8$8, so $4\times2=8$4×2=8.