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:3:23

- [Voiceover] If you up all of the spots on these dominoes, there are 63 spots. So if you counted all of these dots, they're telling us that would be 63. So we don't have to do that. And then they tell us,
that is 42 more spots than the total number of
spots on a six sided die. So they're saying if you
took a six sided die, so a six sided die, might
look something like this. It's a cube, it might have one dot and then it might have
three and then over here it might have maybe two
and so if you count up all of these dots, the ones we see and then the ones on
the other side as well, that's the number of
spots on a six sided die. Now what they're saying
is that the 63 spots, they said if you add up all the spots on these dominoes there is 63. And they're saying that is 42 more spots than the total number of
spots on a six sided die. Let's now figure out how many spots are on a six sided die. The first thing you should
always ask yourselves is what they're asking for. Is this going to be more or less than the number of spots that
you have on these dominoes? You might say, "Hey, I'm reading 42 more "I see this word more, there
must be 42 more spots." But you have to be very,
very, very, very careful. Whenever you do a word problem, don't just look for words and say "Oh it's more I'll add or if
it's fewer I'll subtract." Because that's not going
to be the case always. You really need to think about what is the problem asking for? Because they're saying that
this 63 dots right over here that is 42 more than the
total number of spots on a six sided die. Another way of thinking about it is, if you took the number of
spots on a six sided die that's what they're asking for. So if we say that's question mark. If you took the number of
spots on a six sided die and you had 42 more than that, then that is going to be equal to the number of spots on these dominoes and they tell us that is 63. The number of spots on a
six sided die plus 42 is 63 or 63 spots is 42 more
spots than the total number of spots on a six sided die. Always think about what they're saying. So now we can try to figure out what this question mark is. Well if question mark
plus 42 is equal to 63, that's the same thing as
saying that question mark is equal to 63, 63 minus 42. So what's that going to be? We can calculate it. So 63, six tens three ones. 42, four tens and two ones. We want to subtract that, and when we do we're going to figure
out the number of spots on the six sided die. We'll go to ones place, three ones minus two ones is one one. Six tens minus four
tens, those are two tens. So two tens and one one that's 21 spots. 21 spots on a six sided die.