To write 3.40 as a fraction you have to write 3.40 as numerator and put 1 as the denominator. Now you multiply numerator and denominator by 10 as long as you get in numerator the whole number.
3.40 = 3.40/1 = 34/10
And finally we have:
3.40 as a fraction equals 34/10 simplified we get: 3 2/5
