1. Convert 0.7 and 4.2 to fractions:
0.7 = \frac{7}{10}
4.2 = \frac{42}{10}
2. Multiply the fractions:
\frac{7}{10} \times \frac{42}{10} = \frac{7 \times 42}{10 \times 10} = \frac{294}{100}
3. Convert the fraction back to a decimal:
\frac{294}{100} = 2.94
Therefore, the value of the expression is:
0.7 \times 4.2 = 2.94