In this lesson, students will learn how to compute differences within 1000 using the break apart strategy. |
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One strategy for subtraction is the break apart strategy. To use this strategy, follow the procedure below:
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We wish to find the value of 646 - 315 Breaking these numbers apart, we have 646 = 600 + 40 + 6 and 315 = 300 + 10 + 5 First, subtract the hundreds 600 - 300 = 300 Next, subtract the tens 40 - 10 = 30 Then, subtract the ones 6 - 5 = 1 Finally, add those three values together 300 + 30 + 1 = 331 Thus, we know that 646 - 315 = 331 |
Ali ran for 258 feet and Katy ran for 124 feet. What is the difference between the two distances? We wish to find the value of 258 - 124 Breaking these numbers apart, we have 258 = 200 + 50 + 8 and 124 = 100 + 2 + 4 First, subtract the hundreds 200 - 100 = 100 Next, subtract the tens 50 + 20 = 30 Then, subtract the ones 8 - 4 = 4 Finally, add those three values together 100 + 30 + 4 = 134 Thus, we know that 258 - 124 = 134 This means that difference between the distance that Ali ran and the distance that Katy ran is 134 feet. |
Watch as a the robots move in the grid. Notice that the first robot moves 376 inches then backwards 235 inches. It ends at the position of 141 inches. Thus, 376 - 235 = 141 The second robot moves the same amount but it does so by breaking 376 and 235 apart. We have that 376 = 300 + 70 + 6 and 235 = 200 + 30 + 5 First, the robot moves 6 - 5 = 1 Next, the robot moves 70 - 30 = 40 Then, the robot moves 300 - 200 = 100 Finally, adding all of these values together we have 1 + 40 + 100 = 141 Thus, we know that 376 - 235 = 141 This means that both robots' final position is 141 inches. |
