Easy Subtraction Technique for Students
Learn an easy subtraction method to avoid subtraction difficulties, using column techniques with increases to simplify calculations. Master subtracting negative numbers with this method.
Easy Subtraction Technique for Students
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Presentation Transcript
Numbers This technique avoids the need to subtract a large number from a small number, always a difficult task for students. Easy Subtraction! The column method requires we borrow, carry …. and get confused!
Numbers 301 – 57 is a very awkward calculation…
Numbers So lets make it easier! Place the numbers in a column as normal 301 57
301 304 344 +3 = +40 = Numbers 57 60 100 +3 = +40 = Increase BOTH numbers by 3 so 57 becomes 60 Increase BOTH numbers by 40 so 60 becomes 100 Now subtract 100 from 344! Answer is 244! EASY!! .
423 425 445 +2 = +20 = Numbers 78 80 100 +2 = +20 = 345 . 738 739 749 +1 = +10 = 589 590 600 +1 = +10 = 149
751 757 Each increase, check to see if the subtraction can be carried out without another increase. +6 = Numbers 224 230 +6 = 527 . 1767 1769 +2 = 538 540 +2 = 1229
This techniques works for calculating negative numbers too. You just need to work upside down! Numbers -252 . 267 270 300 +3 = +30 = 523 526 556 +3 = +30 =