p. 1

subtraction borrowing subtraction borrowing subtraction borrowing say we have to compute 2 3 now if we do 2-3 -1 and if we place the number as 3-2 it equals 1 hence commutative property is not applicable to subtraction associative property also does not exist for subtraction say we have 2 3-4 2 1 3 now if we change the order of subtraction 2-3 4 -1-4 5 hence associative property also does not exist for subtraction.suppose you know how to start you write 9000 584 then you try to subtract in the ones column 0 4 you can t do that since 4 is greater than 0 so you go to borrow from the tens column that s where you run into trouble because the tens column doesn t have anything to borrow it s like going next door to borrow a cup of sugar and the lady there is all out of sugar too what do you do well this may not make much sense with sugar but with numbers we do this we send the lady next door to her neighbor to borrow some sugar so she will have some to lend so we go on to the hundreds place to borrow a 1 but we find that this place doesn t have anything to lend either well we have one last place to try the thousands column there finally we find something to borrow so we borrow we reduce the 9 to 8 and change the know more about a rectangle math.edurite.com page 1/3

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p. 2

1 thousand that we borrowed into 10 hundreds 8 10 0 0 5 8 4 we can t stop there though we still can t subtract in the ones column now that the hundreds column has something to be borrowed the tens column borrows one of those 10 hundreds that leaves 9 hundreds and the 1 hundred we borrowed becomes 10 tens 8 9 10 0 5 8 4 now that the tens column has something to be borrowed the ones column borrows one of those 10 tens that leaves 9 tens and the 1 ten we borrowed becomes 10 ones 8 9 9 10 5 8 4 at last we can do the subtraction all the way through 8 9 9 10 5 8 4 8 4 1 6 the answer is 8416 now that looks like a lot of work i don t actually write down all that stuff i just go straight to this 8 9 9 9 0 0 10 5 8 4 8 4 1 6 that s not quite how i write it i can t cross out the digits on the computer and the 1 i insert is tiny and raised you know how to write it what matters is that i know right away that i m going to have to borrow 1 for the ones column from the thousands column the first column to the left that has something to borrow therefore i change 1000 into 999 1 leaving 8999 and one more to add into the ones column making 10 in the ones column read more about definition of real number math.edurite.com page 2/3

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p. 3

thank you math.edurite.com

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