OK, let's crack this. We're given 7 and our task is to multiply it by 31. Essentially, we'll be adding 7 to itself 31 times.
Step 1: 0 + 7 = 7
Step 2: 7 + 7 = 14
Step 3: 14 + 7 = 21
Step 4: 21 + 7 = 28
Step 5: 28 + 7 = 35
Step 6: 35 + 7 = 42
Step 7: 42 + 7 = 49
Step 8: 49 + 7 = 56
Step 9: 56 + 7 = 63
Step 10: 63 + 7 = 70
Step 11: 70 + 7 = 77
Step 12: 77 + 7 = 84
Step 13: 84 + 7 = 91
Step 14: 91 + 7 = 98
Step 15: 98 + 7 = 105
Step 16: 105 + 7 = 112
Step 17: 112 + 7 = 119
Step 18: 119 + 7 = 126
Step 19: 126 + 7 = 133
Step 20: 133 + 7 = 140
Step 21: 140 + 7 = 147
Step 22: 147 + 7 = 154
Step 23: 154 + 7 = 161
Step 24: 161 + 7 = 168
Step 25: 168 + 7 = 175
Step 26: 175 + 7 = 182
Step 27: 182 + 7 = 189
Step 28: 189 + 7 = 196
Step 29: 196 + 7 = 203
Step 30: 203 + 7 = 210
Step 31: 210 + 7 = 217

So, 7*31 = 217