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4 times even number

Rules:

a. Write half the even number and put 0 at the end.

b. Subtract the same even number from the answer at (a).

Examples:
4 x 2; Half of 2 is 1. Put 0 at the end to form10. Subtract the 2 from the 10.
That is 10 - 2 = 8. Hence 4 x 2 = 8

4 x 4; Half of 4 is 2. Put 0 at the end to form 20. Subtract the 4 from the 20.
That is 20 - 4 = 16. Hence 4 x 4 = 16.

4 x 12; Half of 12 is 6. Put 0 at the end to form 60. Subtract the 12 from the 60.
That is 60 - 12 = 48. Hence 4 x 12 = 48.




4 times odd number


Rules:

a. Write half of the odd multiplier down.

b. Reject the decimal point to get a whole number.

c. Subtract the odd multiplier from the answer at (b).

Examples:

4 x 1; Half of 1 is 0.5. Reject the decimal point to get 5. Subtract the 1 from
the 5. That is 5 - 1 = 4. Hence 4 x 1 = 4.

4 x 3; Half of 3 is 1.5. Reject the decimal point to get 15. Subtract the 3 from
the 25. That is 15 - 3 = 12. Hence 4 x 3 = 12.

4 x 13; Half of 13 1s 6.5. Reject the decimal point to get 65. Subtract
the 13 from the 65. That is 65 - 13 = 52. Hence 4 x 13 = 52.