First questions answer is:
23.4 - 8.78 = 14.62
you subract 23.4 by 8.78. Since the number 23.4 is bigger than 8.78, the answer is not negative.
how you subtract the two numbers are you line up the decimal points, and then add a 0 next to the 4 in the term 23.4, and just subtract the two terms, 8.78.
Second question answer is:
4
if you add 2+4 you get 6.
Third question answer is:
$110
you add 47.91 + 23.96 + 35.09 and you get 106.96, which is closest to 110, so She spent about $110
Hope this helped, if I'm wrong on anything, feel free to correct me
