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Hovedindhold

Aktuel tid:0:00Samlet varighed:3:37

- [Voiceover] Jacques took a submarine to the bottom of the ocean and discovered an underwater city. The starfish ruled the city. This is fascinating. There were 59 seahorses there, which was 28 fewer than the number of starfish. 28 fewer than the number-- I already used that color. Than the number of starfish. How many starfish, how
many starfish were there? So let's think about this
second sentence, here. So, number of seahorses is 28 fewer than the number of starfish. So we could write, we could write, number of seahorses, seahorses, is 28 fewer than
the number of starfish. So that means that this is going to be equal to then number of starfish. Number of starfish, starfish minus 28. 28 fewer than the number of starfish. So, let me write that in blue. So, if I have the number of starfish, and I go 28 fewer than that, that's going to be the
number of seahorses. That's what they tell us. The number of seahorses. "There were 59 seahorses there, "which was 28 fewer than
the number of starfish." And, they actually tell us what the number of seahorses is. It's 59, so we could write this as-- We could write this as, 59 is equal to the number of starfish. Number, actually maybe I'll just draw-- well I'll write it out, starfish. The number of starfish minus 28. Minus 28. Or, another way to think about it is there's 28 more starfish than seahorses. So we could rewrite this as saying, well whatever the number of seahorses are, whatever the number of seahorses are, they tell us, there's 59 seahorses. There's going to be 28 more. There's going to be 28 more starfish. Whenever you do a problem like this, it's always a good idea
just to do a check. Just to say, "Okay, are
there going to be more "starfish or more seahorses?" And when you look at the
information they give us, they say they there are 59 seahorses which was 28 fewer than
the number of starfish. So, if there are fewer
seahorses than starfish, that tells you there's
going to be more starfish. So it makes sense. If you want to go from the seahorses, the number of seahorses
to the number of starfish, you would add 28 because there is more starfish than seahorses. So now we just have to figure out what 59 plus 28 is, so let's do that. So, 59 is five 10s, and nine, ones. 28, let's write the two
10s in the 10s place, and the eight ones, in the one's place. We're adding. We're going to go from the number of seahorses add 28 more than that to get to the number of starfish. So let's first go to the one's place. Nine ones, plus eight ones is 17 ones. Write the seven ones, and one 10, or you could think of
it as I carried the one. But all I did was I
wrote the one 10 in 17, I wrote that in the ten's place. And now I could add one 10, plus five 10, plus two 10s. So let's see. One, plus five, plus two is eight. Eight tens. So the number of starfish is 87. And you should always
see if that makes sense. The number of starfish is, this right over here, is 87. So, if there are 59 seahorses, is that 28 fewer than 87? Sure, it is. It's exactly 28 fewer. Like, that's what we used
to solve this question.