1. The problem asks us to evaluate the expression $7b$ when $b=6$. 2. The expression is a simple multiplication: $7b$ means $7 \times b$. 3. Substitute the value of $b$ into the expression: $$7b = 7 \times 6$$ 4. Multiply the numbers: $$7 \times 6 = 42$$ 5. Therefore, the value of the expression when $b=6$ is $42$.