$(-5) \times 4=$ $3 \times 7=$ $8 \times 3=$ $8 \times 5=$ $(-9) \times 7=$ $(-9) \times 1=$ $9 \times 5=$ $7 \times(-6)=$ $(-9) \times(-6)=$ $7 \times(-2)=$ $4 \times 2=$ $(-1) \times 7=$ $(-1) \times 4=$ $9 \times 0=$ $5 \times(-5)=$ $(-9) \times(-4)=$ $3 \times 8=$ $0 \times 0=$ $9 \times(-3)=$ $(-6) \times 4=$

Step 1 ：Given the math problems are $(-5) \times 4$, $3 \times 7$, $8 \times 3$, $8 \times 5$, $(-9) \times 7$, $(-9) \times 1$, $9 \times 5$, $7 \times(-6)$, $(-9) \times(-6)$, $7 \times(-2)$, $4 \times 2$, $(-1) \times 7$, $(-1) \times 4$, $9 \times 0$, $5 \times(-5)$, $(-9) \times(-4)$, $3 \times 8$, $0 \times 0$, $9 \times(-3)$, $(-6) \times 4$

Step 2 ：The product of $(-5) \times 4$ is $-20$

Step 3 ：The product of $3 \times 7$ is $21$

Step 4 ：The product of $8 \times 3$ is $24$

Step 5 ：The product of $8 \times 5$ is $40$

Step 6 ：The product of $(-9) \times 7$ is $-63$

Step 7 ：The product of $(-9) \times 1$ is $-9$

Step 8 ：The product of $9 \times 5$ is $45$

Step 9 ：The product of $7 \times(-6)$ is $-42$

Step 10 ：The product of $(-9) \times(-6)$ is $54$

Step 11 ：The product of $7 \times(-2)$ is $-14$

Step 12 ：The product of $4 \times 2$ is $8$

Step 13 ：The product of $(-1) \times 7$ is $-7$

Step 14 ：The product of $(-1) \times 4$ is $-4$

Step 15 ：The product of $9 \times 0$ is $0$

Step 16 ：The product of $5 \times(-5)$ is $-25$

Step 17 ：The product of $(-9) \times(-4)$ is $36$

Step 18 ：The product of $3 \times 8$ is $24$

Step 19 ：The product of $0 \times 0$ is $0$

Step 20 ：The product of $9 \times(-3)$ is $-27$

Step 21 ：The product of $(-6) \times 4$ is $-24$

Step 22 ：Final Answer: \(\boxed{-20}\)