Mental Quick conversions:

[David Morton]

Another stupid but simple conversion:
For Km/h to MPH:


Half the speed four times and multiply the result by 10

160Km/h = 80 = 40 =20=10 x10 = 100 mph.

For MPH TO km/h
Divide by 10 and double it 4 times.

Lbs to Kg:
Half it and knock of 10%
Kg to Lbs:
Double it and add 10%.

Any more???

 

[Ian Anderson]

inch to cm divide inch by 4 then multiply by 10 (4 inch = 4/4*10 = 10cm)

6/10 is fair estimate Miles to km (60miles 60/6 * 10 = 100km)

Yards to meters 1 meter = 1.1 yards (or 40 inches) or the height of our favourite car!

Ian

 

[Tod]

Liters x 61 = Cubic Inches