Multiplyby | Trick |
---|---|

2 | add the number to itself (example 2×9 = 9+9) |

5 | the last digit goes 5, 0, 5, 0, ... |

is always half of 10× (Example: 5x6 = half of 10x6 = half of 60 = 30) | |

is half the number times 10 (Example: 5x6 = 10x3 = 30) | |

6 | when you multiply 6 by an even number, they both end in the same digit. Example: 6× 2=12, 6×4=24, 6×6=36, etc |

9 | the last digit goes 9, 8, 7, 6, ... your hands can help! Example: to multiply 9 by 8, hold your 8th finger down, and count "7" and "2", the answer is 72 |

is 10× the number minus the number. Example: 9×6 = 10×6−6 = 60−6 = 54 | |

when you add the answer's digits together, you get 9. Example: 9×5=45 and 4+5=9. (But not with 9×11=99) | |

10 | put a zero after it |

11 | up to 9x11: just repeat the digit (Example: 4x11 = 44) |

for 10x11 to 18x11: write the sum of the digits between the digits Example: 15x11 = 1 (1+5)5 = 165 Note: this works for any two-digit number, but when the sum of the digits is more than 9, we need to"carry the one". Example: 75x11 = 7(7+5)5 = 7(5 = 12)825. | |

12 | is 10× plus 2× |

Key Words : Nobel Prize 2014, Kerala PSC, Secretariat Assistant