5 4
+ 3 2
8 6
on
es
hu
nd
red
s
ten
s
REGROUPING
in Addition
6
3
9
When we add numbers in
columns, we can think of
each column as being a set.
We add up all the numbers in
each set.
First we add all the numbers
in the ones place, then we
add all the numbers in the
tens place, then we add all
the numbers in the
hundreds place, and so on.
When we have more than 9 in a set, we have to
regroup—we have to move any of the digits that are
higher than 9 over to the next column.
Sometimes, we
don’t even think
about the process.
1
0 6
+0 5
1 1
6
+ 5
11
© 2007abcteach.com
REGROUPING
in Addition
When we have more
than 9 in a set, we
regroup—we move the
tens place digit over to
the next column.
Sometimes we can do
this without thinking...
But it’s a good idea to be
aware of the process, for
when problems get more
complicated.
1
0 6
+0 5
1 1
6
+ 5
11
1
0
+0
1
1
8
5
4
1
9 6
3 5
3 1
11
5
3
+ 1
10
2
8
2
5
7
2
5
9
7
3
4
8
9
1
© 2007abcteach.com
REGROUPING
in Addition
When adding a very long column of numbers, one way to
regroup is to make a mark above the next column every
time the number goes over 9 (that is, every time there is a
digit in the tens place), and start again.
1
1 1
1 1
2
3
9
7
8
+ 1
3 2
5
2
8
2
5
7
9
ONES column:
5+2=7
7 + 8 = 15 (regroup 10, continue with 5)
5+2=7
7 + 5 = 12 (regroup 10, continue with 2)
2+7=9
TENS column
1+1=2
2+2=4
4+3=7
7 + 9 = 16 (regroup 10, continue with 6)
6 + 7 =13 (regroup 10, continue with 3)
3 + 8 = 11 (regroup 10, continue with 1)
1+1=2
HUNDREDS column
1+1+1=3
© 2007abcteach.com