203
- = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( )
% < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9
( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8
9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7
8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6
7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5
6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3
Children often ask me, “How do I use the methods in the classroom?
Won’t my teacher object if I use diff erent methods?”
It is a fair question. Here is the answer I give.
First, many of the methods taught in this book are “invisible.” Th at
is, the diff erence is what you say in your head. With addition and
subtraction problems, the layout and written calculations are the
same; what is diff erent is what you say to yourself in your head.
When you are subtracting 8 from 5 and you borrow 10 to make it
8 from 15, you say to yourself, 8 from 10 is 2, plus 5 is 7. You write
down the 7. Th e students who subtract 8 from 15 write down 7 as
well (so long as they don’t make a mistake), so anyone looking over
your shoulder would have no idea you are using a diff erent method.
Th e same goes for subtracting 3,571 from 10,000. You set the
problem out the same as everyone else, but again, what you say
inside your head is diff erent. You subtract each digit from 9 and
the fi nal digit from 10. No one looking at your fi nished calculation
would know you did anything diff erent.
U USING THE METHODS SING THE METHODS
IIN THE CLASSROOMN THE CLASSROOM
AAppendix Appendix A
bbapp01.indd 203app 01 .indd 203 1 1/5/07 11:35:38 AM/ 5 / 07 11 : 35 : 38 AM
- = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( )