Answer:
You would add the number of blue Cars to the number of red cars.
Step-by-step explanation:
29
+31
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Add 1 to 9 which gives u 10. Put down the zero and carry the 1 put it above the 2. Add 3 to 2 and add the 1 which u put above the 2 and u get 60.
Or, take away 1 from 31 and make it 30. Add that 1 to 29 and make it 30 as well, once u get 30+30 just add and get 60
