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Which of these is not equal to nine?
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12 take away two.
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10 take away one.
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17 take away eight.
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14 take away five.
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15 take away six.
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Let’s start by checking 12 take away two.
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We could partition number 12 into 10 and two.
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And if we were to take away the two, we would have 10 left.
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12 take away two equals 10.
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So, the first expression is not equal to nine.
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Is 10 minus one equal to nine?
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Well, here, we have 10 counters in our 10 frame.
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And if we take away one, we will be left with nine.
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10 take away one equals nine.
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Does 17 take away eight equal nine?
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Well, we can partition 17 into 10 and seven.
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We can take away the seven.
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One, two, three, four, five, six, seven.
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That leaves us with 10.
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But we need to take away eight, so we have to take away one more.
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17 take away eight is nine.
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Does 14 take away five equal nine?
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Well, we can partition 14 into 10 and four.
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Take away the four to leave us with 10.
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And then, take away one more, which will leave us with nine.
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14 take away five equals nine.
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If we have 15 and we take away six, we’ll also be left with nine.
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15 take away five is 10, take away one more is nine.
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All of the expressions equal nine, except the first one.
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The expression which is not equal to nine is 12 take away two.