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I have two-quarters, two dimes, and one penny.
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Which coins can I add to make one dollar?
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We’re trying to make a total of one dollar.
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In order to do that, we’ll need to know how much money I already have.
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Two-quarters, two dimes, and one penny add up to how much money?
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How much money is two-quarters equal to?
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We would multiply the two-quarters I have by the value of one-quarter.
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Two times 25 cents equals 50 cents.
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25 plus 25 equals 50.
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We can follow the same procedure for our two dimes: two multiplied by 10 cents.
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Two times 10 equals 20.
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Two times 10 cents equals 20 cents.
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One penny is equal to one cent.
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And we write that 0.01.
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And then, we add all these three values together: 50 cents plus 20 cents plus one cent.
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All the way on the right, we have zero, zero, one.
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Zero plus zero plus one equals one.
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Moving to the left, five plus two equals seven.
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Bring down the decimal point, bring down the zero, and bring down the dollar sign.
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We have 71 cents and we need one dollar.
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To find out how much money we need, we subtract 71 cents from one dollar.
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Starting all the way on the right, we can’t subtract one from zero.
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So we borrow and then we have one taken out of 10.
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10 minus one equals nine and nine minus seven equals two.
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Bring down the decimal place.
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Zero minus zero equals zero and copy down our dollar sign.
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We are missing 29 cents.
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Which of the answer choices on the left is equal to 29 cents?
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Answer choice a has two dimes that equals 20 cents and four nickels.
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Nickels are worth five cents and we have four of them.
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Four times five is 20.
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This means that answer choice a is too much.
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We’ve already discovered that four nickels equals 20 cents, four pennies equals four cents, 20 cents plus four cents equals 24 cents.
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Answer choice b is not enough.
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Moving on to answer choice c, one-quarter equals 25 cents, four pennies equals four cents, 25 cents plus four cents equals 29 cents — the exact amount we were looking for.
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By adding one-quarter and four pennies to the money I already have, I will have exactly one dollar.
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Answer choice d and e are both too much, leaving us with a final answer of one-quarter and four pennies.