If sam has 10 marbles and he throw away 7 then gain 300 more but takes away 50 marbles how many marbles does Sam have left over

Answer 1

This problem could be modeled as:

10 - 7 + 300 - 50

Using the correct order of operations (i.e. add or subtract in the order shown from let to right):

10 - 7 =3

3 + 300 = 303

303 -50 = 253 marbles left