3-48 Regrouping More Than Once

Look at the problem below.

TH	H	T	O
5	0	0	0
1	5	6	7

Sometimes during subtraction, you may need to regroup more than one time.  Since you cannot take 7 from 0, you will need to borrow from the tens column.

Since the tens column is also a 0, you will need to borrow from the hundreds column.

Again, the hundreds column is also a 0.  Since you cannot borrow from the hundreds column, you must look to the thousands column.

Look at the problem below.

First subtract the ones. You cannot take 7 from 0. Borrow from the tens.  The tens column has a zero in it.  So you must look to borrow from the hundreds column.  Again the hundreds column has a zero in it.   You must look to borrow from the thousands column.  Borrow 10 hundreds to the hundreds column.   TH H T O 4 10 0 0 1 5 6 7	Next borrow 10 tens to the tens column.                 TH H T O 4 9 10 0 0 1 5 6 7
Now borrow 10 tens to the ones column.         TH H T O 4 9 9 10 1 5 6 7	Subtract the the ones column. Then the tens column. Next the hundreds column. And the thousands column.   TH H T O 4 9 9 10 1 5 6 7 3 4 3 3

Solve the problems below.

Borrow from the thousands column.   TH H T O 6 0 0 3 6 7 8	Borrow from the hundreds.     TH H T O 6 9 0 3 6 7 8
Borrow from the tens column.   TH H T O 6 9 9 3 6 7 8	Subtract.   TH H T O 6 9 9 10 3 6 7 8

TH H T O 9 9 10 2 8 6 4	TH H T O 9 9 2 5 3 8	TH H T O 5 3 9 7 5
TH H T O 5 2 8 9	TH H T O 4 9 7 4	TH H T O 1 8 6 5
7 0 0 0 1 6 6 6	6 0 0 0 2 4 7 1	9 0 0 0 6 5 3 2
8 0 0 0 1 7 5 3	7 0 0 0 6 4 2 2	5 0 0 0 1 5 4 1