Solution

011
+234
567
0801

Step 1

1
+234
567
1
4 + 7 = 11
Carry= 1
Unit Value = 1

Step 2

11
+234
567
01
3 + 6 + 1 = 10
Carry= 1
Unit Value = 0

Step 3

11
+234
567
801
2 + 5 + 1 = 8
Carry= 0
Unit Value = 8

Step 4

011
+234
567
0801