Multiplier plus multiplier digits, sum multiplied by ten-digit integer, the product is the front product, and single digits multiplied by single digits is the back product.

For example: 43 × 46

(43 + 6)× 40 = 1960

3 × 6 = 18

-

1978

For example: 89 × 87

(89 + 7)× 80 = 7680

9 × 7 = 63

-

7743