Jenny uses the following method to find 28% of 60,000 mentally: Twenty-five percent is 15, and 4 of 60 is 15. 25% of 60,000 is 15,000. One percent of 60,000 is 600, and that times 3 is 1,800. So the answer is 15,000 + 1,800, which is 16,800. Write a string of equations that calculates 28% of 60,000 and that incorporates Jenny’s ideas: Write your equations in the following form: 28% * 60,000 = 16,800.
The Correct Answer and Explanation is:
Correct Answer:
28% × 60,000 = (25% × 60,000) + (3% × 60,000)
= 15,000 + (1% × 60,000 × 3)
= 15,000 + (600 × 3)
= 15,000 + 1,800
= 16,800
Explanation
To find 28% of 60,000 efficiently, a mental math strategy can break the problem into simpler, manageable parts. This method relies on understanding percentage relationships and their equivalence in whole numbers.
First, 25% is a common and easy benchmark to work with. It represents one-quarter of any value. For 60,000, divide by 4:
60,000 ÷ 4 = 15,000.
Thus, 25% of 60,000 is 15,000.
Next, focus on the remaining 3% that completes the 28%. To find 3%, break it further into three 1% units.
One percent of 60,000 is found by dividing by 100:
60,000 ÷ 100 = 600.
Multiplying 600 by 3 gives the value of 3%:
600 × 3 = 1,800.
Now, add the two components:
25% of 60,000 = 15,000
3% of 60,000 = 1,800
Sum: 15,000 + 1,800 = 16,800
This structured mental breakdown follows Jenny’s reasoning. By using known, easy percentages like 25% and 1%, large calculations become simpler. Each part involves familiar arithmetic: halving, dividing by 100, and small multiplications.
The string of equations mirrors this thought process, combining math facts with percentage reasoning. This technique avoids relying on a calculator and supports faster mental computation, especially with round numbers like 60,000. Such strategies are often used in quick financial estimations, budgeting, or test scenarios where time efficiency is important.
Therefore, the final result of 28% of 60,000 is:
16,800.
