The first one is 50 cm
second is 153 ft
third one is 132 m
sorry if it’s wrong
7(1 + 3) = (7 x 1) + (7 x 3) = 7 + 21
What you would do is round 47.6 to 48. You would then round 39.75 to 40. Then you add 48 & 40 to get 88.
I hope it would be helpful for u