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Trade First Algorithm for Subtraction. Created by Paula Cantera Elk Neck Elementary. The trade first algorithm is a two stage process. First, working right to left do all of the borrowing. Next, in any order, do the subtractions. 325. -. 58. In the problem above you see
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Trade First Algorithmfor Subtraction Created by Paula Cantera Elk Neck Elementary
The trade first algorithm is a two stage process. • First, working right to left do all of the borrowing. • Next, in any order, do the subtractions
325 - 58 In the problem above you see that the ones column needs borrowing.
1 15 (10 + 5) 325 - 58 We will trade in one of the tens for ten ones.
1 15 325 - 58 We also see that the tens column needs borrowing .
11 (10 + 1) 2 1 15 325 - 58 We will trade in one of the hundreds for ten tens.
11 2 1 15 325 - 58 You are now ready to subtract. You can do the subtractions in any order.
11 2 1 15 15 - 8 = ? 325 - 58 11 - 5 = ? 2 - 0 = ? 2 6 7
Or we could do it in this order.. 11 2 1 15 2 - 0 = ? 325 11 - 5 = ? - 58 15 - 8 = ? 2 6 7
Trade First Algorithm for Subtraction • Another way to subtract multi-digit numbers. Try it!
