There are 40 students in a class and 30% of these students passed their history test. What
number of these students passed the test?

12 people passed out of 40. thats a pretty bad teacher ._.

Step-by-step explanation:

30% of 40=12

the 8 in 8,420 is in the thousands place so it's value is 8 thousand.

the 8 in 6,870 is in the hundreds place so it's value is 8 hundred.

divide 8000 by 800 to find the answer:

8000 / 800 = 10

the 8 in 8,420 is 10 times greater than the 8 in 6,870