THE NEW STUDENT'S REFERENCE WORK 2145
Add rapidly by lines and columns:
8 + 5 + 3 + 4 + 6 =
5 + 4 + 6 + 9 + 2 =
2 + 7 + 8 + 5 + 4 =
3 + 9 + 4 + 6 + 8 = 7 + 4 + 5 + 7 + 3 =
4 + 6 + 7 + 8 + 2 =
+ + + + =
A chart like the above demands the pupils7 close attention and ready response, if the teacher will point to a series of numbers in rapid succession.
Objective work in addition after 10 has been taught, should gradually give way to method.
Three classes of examples should be taught:
1. Where the sum of the units is less than 10,
as 22+4; 33+5; 64+3, etc.
2. Where the sum of the units exactly equals 10,
as 22+8; 33+7; 64+6, etc.
3. Where the sum of the units exceeds 10,
as 22+9; 33+8; 64+9, etc.
Extend this work to numbers of more than two places in exactly the same way, emphasizing method of work.
428 486 596 482 825 645
351 214 678 675 642 547
725 826
779 700 1274
Add 425 In adding long columns it is often found convenient to
638 write the sum of each column, placing the right-hand figure
764 under the column added.
825 In case of error, it enables one to find the mistake with
655 less difficulty. 124
31 20 32 3431
