We want to calculate the following product
To do so, we will use some properties of the product. First, note that 22=20+2. So we have
Now, we will use the distributive property, so we get
Now, this suggests that we can calculate 80*2 and 80*20 separately and then add the results together.
So now, we want to calculate first
Note that 80=8*10. So we have
We can rearrange the order of the product as follows
We know that 8*2=16. So we have
NOw, recall that multiplying by 10 can be done by simply adding a 0 in the right end of the number, so we get
Now, we want to calculate 80*20. So we have
Recall that 20=2*10. Then
We already know that 80*2=160. Then
By applying the same principle of multiplying by 10, we have
Now, we add both solutions, so we have