To find out how many lies the boy told before he went to bed, we can count each instance where he lied:
- To his teacher about his homework.
- To his mom about his grades.
- To his sister about taking her to the park.
- To his bus driver.
- To his friend.
- To his pet pal.
- To his dad about his grades.
- To his mom about him being hungry.
Summing these up, the boy told a total of 8 lies before he went to bed.