WEBVTT
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Students want to plant 621 trees in their village.
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They have planted 476 trees.
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How many are left?
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When we’re solving word problems, we always begin by highlighting the key numbers and phrases.
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Students want to plant 621 trees.
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They have already planted 476.
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So we need to calculate how many trees they still have left to plant.
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Now we have our key words and numbers, we can record our equation.
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Students had 621 trees to begin with.
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They planted 476.
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Did the students add 476 trees or take them away?
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That’s right!
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They took them away.
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They took them away to plant them.
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The correct operation to use is minus, 621 minus 476.
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This will tell us how many trees are left to plant.
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Now what we need to do is calculate the answer using column subtraction, 621 minus 476.
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We start in the ones column.
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And we need to calculate one minus six.
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The bottom number six is greater than one.
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So we’re gonna have to take a 10 from the tens column.
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We’ve taken a 10 from the tens column and placed it in the ones column.
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Now we can calculate 11 minus six, which is five.
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Next, we move into the tens place.
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We need to calculate one minus seven.
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Again, the bottom number is greater than the top number.
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So we need to regroup.
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We’ve taken one from the hundreds column and we’ve added it to the tens column.
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So now we can calculate 11 minus seven, which is four.
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Now we can move into the hundreds column.
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And we need to calculate five minus four, which is one.
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621 minus 476 equals 145.
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Students had 621 trees.
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They planted 476.
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They still have 145 trees left to plant.
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We calculated our answer using column subtraction.