1. **State the problem:** We have a row of 3 identical squares made using 10 toothpicks. We want to find how many toothpicks are needed to make a row of 11 such squares. 2. **Analyze the pattern:** - Each square has 4 sides. - When squares are placed in a row, they share sides with adjacent squares. - For 3 squares, the total toothpicks used is 10. 3. **Find the formula for toothpicks in a row of $n$ squares:** - The first square requires 4 toothpicks. - Each additional square adds 3 toothpicks (since it shares one side with the previous square). So, total toothpicks for $n$ squares is: $$4 + 3(n - 1) = 3n + 1$$ 4. **Verify with given data:** For $n=3$: $$3(3) + 1 = 9 + 1 = 10$$ Matches the given number. 5. **Calculate for $n=11$:** $$3(11) + 1 = 33 + 1 = 34$$ **Final answer:** 34 toothpicks are needed to make a row of 11 squares.