1. The problem is to convert the fraction $\frac{21}{70}$ to a decimal. 2. To convert a fraction to a decimal, divide the numerator by the denominator. 3. Perform the division: $$\frac{21}{70} = 21 \div 70$$ 4. Simplify the fraction first by dividing numerator and denominator by their greatest common divisor, which is 7: $$\frac{\cancel{21}^3}{\cancel{70}^{10}} = \frac{3}{10}$$ 5. Now divide 3 by 10: $$3 \div 10 = 0.3$$ 6. Therefore, the decimal equivalent of $\frac{21}{70}$ is $0.3$.