If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content
Current time:0:00Total duration:1:45

Video transcript

a common house spider has eight eyes if a spider is looking at you with two it's two front eyes and three of its other eyes and three of its other eyes what fraction of its eyes are looking at you and just to show that we're not making this stuff up this is actually pictures of spiders and you see in every one of these pictures they have eight eyes even this one two other eyes right over here one two three four five six seven eight I never even realized this this is actually quite quite creepy but anyway let's actually focus on the problem so it's looking at you with two its front eyes two of its two of its eight eyes so the two front eyes represent what fraction of the eyes well it represents two of the eight two of the eight eyes you could look at it right over here you have eight eyes maybe the two front eyes it's one and two of the eight and it says it's also looking at us with three of its other eyes so it's also looking at us with three of the eight eyes and so you could imagine that might be that one that one and that one so this is really about adding fractions this is about adding two eighths of something to three eighths of something so what fraction of its eyes are looking at us are looking at us well it's still going to be a fraction of eight it's going to be still out of eight two plus 3/2 plus three over eight 2 plus three over eight which is just going to be equal to five eighths of the eyes five out of the eight eyes are looking at us and we see it right over here one two three four five five of the total of eight eyes are looking at us in a fairly creepy way