One technique is the one we usually follow by converting the binary number to decimal.

1111010 = -64+32+16+8+2=-6

00001010 = 10

-6*10=-60

This one is different :

Evaluate booth's encoding for both of them..

Eg: -14 = (10010) in 2's complement. It's booth encoding is

-10+1-10.

2^{4} |
2^{3} |
2^{2} |
2^{1} |
2^{0} |

-1 | 0 | +1 | -1 | 0 |

So, (-1)*2^{4 }+ (+1)*2^{2 }+ (-1)*2^{1}= -16+4-2 =-16+2 =-14

Similarly for given two numbers:

1111010 : Booth's encoding is 0-1+1-10

2^{4} |
2^{3} |
2^{2} |
2^{1} |
2^{0} |

0 | -1 | 1 | -1 | 0 |

= -8+4-2= -6

and 00001010 : Booth's encoding is 0+1-1+1-10

2^{5} |
2^{4} |
2^{3} |
2^{2} |
2^{1} |
2^{0} |

0 | +1 | -1 | +1 | -1 | 0 |

+16-8+4-2= 20-10=10.

-6*10=-60

Ignore this if you find it time taking..I found this method recently that is why thought of sharing :P