To make the balloon bigger (hypertrophy), one can either add more water to the balloon, thereby stretching it to its maximum capacity (increase cell volume) or one could theoretically add more rubber (balloon material) to make the overall size of the balloon larger (increase in contractile protein).
The child and dependent care tax credit is a percentage of your day care expenses up to $3,000 for one dependent or $6,000 for two or more dependents. That's not the amount of your credit. It's the amount of day care expenses you can apply the percentage to.
What I can tell you is the amount you can claim as an exemption on your tax return. That would be $3,500. (See line 42 of form 1040.) Most folks also qualify for a $1,000 tax credit, but you need to do the math to find out if you qualify for this credit, the dependent day care tax credit, etc.