29
- = 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
Until now, we have multiplied numbers that were both below the
reference number or both above the reference number. How do we
multiply numbers when one number is above the reference number
and the other is below the reference number?
NUMBERS ABOVE AND BELOW
We will see how this works by multiplying 97 × 125. We will use
100 as our reference number:
100 97 × 125 =
Ninety-seven is below the reference number, 100, so we put the
circle below. How much below? Th ree, so we write 3 in the circle.
One hundred and twenty-fi ve is above, so we put the circle above.
How much above? Twenty-fi ve, so we write 25 in the circle above.
MMULTIPLYING ULTIPLYING AABOVE BOVE
&& BELOW THE BELOW THE
RREFERENCE NUMBEREFERENCE NUMBER
CChapter 4hapter 4
- = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( )