Problem solving

I completed a task called 'Problem solving' with my group.

There is 1 column that shows 4 animals and each of the animals have points. The animals are in a row jumbled up and you have to do addition and subtraction of the points that each animal has to get the answer.

First the question was 5+8+3+3+8-2=??. First I did 3+3=6, then I did 8+8=16, then I did 6+16=22, then I did 22-2=20, then i did 20+5=25.

Next the question was 5+3+8+5-2-2=??. I did 5+5=10, then I did 10+8=18, then I did 18+3=21, then I did 21-2=19, then I did 19-2=17.

Then the question was 5+3+8+3-2-2=??. I did  5+3=8, then I did 8+8=16, then I did 16+3=19, then I did 19-2=17, finally I did 17-2=15.

Last question was 8+8+3+5+5-2=??. I did 5+5=10, then I did 8+8=16, then I did 16+3=19, then I did 19+10=29, finally I did 29-2=27.

I still need to learn how do to place value perfect.