First, we need to work on place values;

If we expand this out, we get

Let's write this another way...  Up and down...

We can add these by making stripes and adding straight down!

Here's a bigger number:

Expand it out:

Stack the numbers in your stripes and add straight down:

Line up the hundreds in the first stripe... Line up the tens in the second stripe... And line up the ones in the third stripe! Easy!