WEBVTT
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Find the two numbers from 10, 20, 60, and zero which add up to 30.
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We have been given a list of four numbers.
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We can only use two of them.
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And we need to add them together to get 30.
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Almost immediately, we can recognize one of these numbers we won’t be able to use.
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We won’t be able to use the number 60 because it is already larger than 30.
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That leaves us with the numbers 10, 20, and zero.
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Can I use the number zero?
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Well, I know that zero plus 30 equals 30.
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But our list of numbers doesn’t include 30.
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And that tells me that I also can’t use zero from this list.
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Now we’re only left with two choices, 10 and 20.
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Now we need to check and see if 10 plus 20 equals 30.
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If we’re adding 10 plus 20, we first add the ones place.
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Zero plus zero equals zero.
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After that, we move on to the tens place.
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One plus two equals three.
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So yes, 10 plus 20 does equal 30.
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From our list of four numbers, we would choose the numbers 10 and 20.