a. 90 cg 95 mg + 7g 12 cg 18 mg
Step 1: Convert measurements so that all has 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
b. 4 kg 2hg + 14 kg + 5 kg 17 hg
Step 1: Convert measurements so that all has same unit. I'll use kg:
1hg = .1kg; Therefore:
2hg = .2kg; 17hg = 1.7
Step 2: Add
4kg + .2kg + 14kg + 5kg + 1.7kg = 24.9kg
c. 12 dag 5 g – 7 g
Step 1: Convert measurements so that all has same unit. I'll use g:
1 dag = 10g; Therefore:
12dag = 120g
Step 2: Subtract
120g - 5g - 7g = 108g
d. 8 kg – 9 hg
Step 1: Convert measurements so that all has same unit. I'll use kg:
1hg = .1kg; Therefore:
9hg = .9kg
Step 2: Subtract
8kg - .9kg = 7.1kg