1. The problem is to calculate $9 \times 2 \times 4$ using the associative law of multiplication. 2. The associative law states that for any numbers $a$, $b$, and $c$, we have: $$ (a \times b) \times c = a \times (b \times c) $$ This means we can group the numbers in any way without changing the result. 3. First, group $9$ and $2$: $$ (9 \times 2) \times 4 $$ Calculate inside the parentheses: $$ 18 \times 4 $$ 4. Multiply $18$ by $4$: $$ 18 \times 4 = 72 $$ 5. Alternatively, group $2$ and $4$ first: $$ 9 \times (2 \times 4) $$ Calculate inside the parentheses: $$ 9 \times 8 $$ 6. Multiply $9$ by $8$: $$ 9 \times 8 = 72 $$ 7. Both ways give the same result, confirming the associative law. **Final answer:** $$ 9 \times 2 \times 4 = 72 $$