Question:
90 cg 95 mg + 7g 12 cg 18 mg
Step 1: Convert measurements so that all have the same unit. I'll use mg:
1 cg = 10mg; 1g = 1000 mg; Therefore:
90cg = 900mg; 7g = 7,000 mg; 12cg = 120mg
Step 2: Add
900mg + 95mg + 7,000mg + 120mg + 18mg = 8,133mg