What is 3.8 x 10^-4 in standard notation?

Please help me! Thanks!

Abig remake 100 loaves of bread in one day how many loaves does the bakery make in 6 days

Landon wrote that 3−2.6=4. which statement about his answer is true?

Meg constructed triangle poq and then used a compass and straightedge to accurately construct line segment os, as shown in the figure below, which could be the measures of angles pos and angle poq?