To express the decimal 0.345 as a fraction, we begin by recognizing its place value. The digit 345 represents 345 thousandths since it is three digits after the decimal point. Therefore, we can write:
0.345 = 345/1000
Next, we should simplify the fraction. To do this, we find the greatest common divisor (GCD) of 345 and 1000, which is 5. We then divide both the numerator and the denominator by 5:
345 ÷ 5 = 69
1000 ÷ 5 = 200
So, the simplified fraction is:
0.345 = 69/200
Therefore, the decimal 0.345 can be expressed as the fraction 69/200.