Fill in the boxes: 1 rupee + 1 rupee = __ rupees, 5 rupees + 5 rupees = __ rupees, 10 rupees + 10 rupees = __ rupees, 20 rupees + 5 rupees = __ rupees, __ rupees + 5 rupees = 10 rupees, 10 rupees + __ rupees = 20 rupees, 20 rupees + __ rupees = 25 rupees, 50 rupees = 20 rupees + 20 rupees + __ rupees, 50 rupees = 10 rupees + 20 rupees + __ rupees, 30 rupees = 20 rupees + 5 rupees + __ rupees.

Step 1: Fill in the boxes by performing the addition or subtraction.

• For $1 \text{ rupee} + 1 \text{ rupee}$: $$1 + 1 = \boxed{2}$$
• For $5 \text{ rupees} + 5 \text{ rupees}$: $$5 + 5 = \boxed{10}$$
• For $10 \text{ rupees} + 10 \text{ rupees}$: $$10 + 10 = \boxed{20}$$
• For $20 \text{ rupees} + 5 \text{ rupees}$: $$20 + 5 = \boxed{25}$$
• For $\boxed{\phantom{5}} \text{ rupees} + 5 \text{ rupees} = 10 \text{ rupees}$: $$10 - 5 = \boxed{5}$$
• For $10 \text{ rupees} + \boxed{\phantom{10}} \text{ rupees} = 20 \text{ rupees}$: $$20 - 10 = \boxed{10}$$
• For $20 \text{ rupees} + \boxed{\phantom{5}} \text{ rupees} = 25 \text{ rupees}$: $$25 - 20 = \boxed{5}$$
• For $50 \text{ rupees} = 20 \text{ rupees} + 20 \text{ rupees} + \boxed{\phantom{10}} \text{ rupees}$: $$20 + 20 = 40$$ $$50 - 40 = \boxed{10}$$
• For $50 \text{ rupees} = 10 \text{ rupees} + 20 \text{ rupees} + \boxed{\phantom{20}} \text{ rupees}$: $$10 + 20 = 30$$ $$50 - 30 = \boxed{20}$$
• For $30 \text{ rupees} = 20 \text{ rupees} + 5 \text{ rupees} + \boxed{\phantom{5}} \text{ rupees}$: $$20 + 5 = 25$$ $$30 - 25 = \boxed{5}$$