Yes, when you are using a kitchen microwave with a lower wattage than the one specified in the package directions, you need to adjust the cooking time accordingly. The general rule is that the higher the wattage of the microwave, the faster it cooks food.
To calculate the adjusted cooking time, you can use the following formula:
Adjusted Cooking Time = (Package Wattage / Microwave Wattage) * Original Cooking Time
In your case, the microwave is 700W, and the package directions are for a 1200W microwave. Let's say the original cooking time mentioned on the package is 4 minutes. To find the adjusted cooking time for your 700W microwave, you would calculate as follows:
Adjusted Cooking Time = (1200W / 700W) * 4 minutes Adjusted Cooking Time = 1.71 * 4 minutes Adjusted Cooking Time ≈ 6.84 minutes
So, you would need to increase the cooking time to around 6.84 minutes in your 700W microwave to achieve similar cooking results as the package directions for a 1200W microwave. Keep in mind that microwaves vary, so it's always a good idea to check the food for doneness during the cooking process, especially when using adjusted cooking times.