Tommy ordered a total weight of 10 kilograms of apple, orange, grape, and strawberry fruits. He ordered 3 kilograms of apples, 1 kilogram of orange, and 3 kilograms of grapes. How many kilograms of strawberries did he order? Let's think first. Chain of thought:
Tommy ordered 3 + 3 + 1 = 7 kilograms of apples, oranges and grapes altogether. Therefore, Tommy ordered 10 - 7 = 3 kilograms of strawberries.
Therefore, the answer is 3.