Multi-step problems with percents

βœ… Understand What Is Given

  • Read the problem carefully.
  • Identify:
    • The original value
    • The percentage
    • What is being asked (increase, decrease, discount, tax, profit, loss, etc.)

πŸ”„ Convert Percent to Decimal or Fraction

  • Percent means β€œout of 100”
  • Convert before calculating:
    • 25% = 0.25
    • 12.5% = 0.125
    • 150% = 1.5

βž•βž– Perform Steps in the Correct Order

Multi-step percent problems usually involve more than one operation:

  • First: Find the percent of a number
  • Next: Add or subtract (for increase or decrease)
  • Sometimes: Repeat with a new percent

πŸ“Œ Always solve step by step, not all at once.


πŸ’Έ Percent Increase Problems

Steps:

  1. Find the increase amount
    β†’ Increase = Original Γ— Percent
  2. Add to the original value

πŸ“˜ Example idea:
Price increases by 10% β†’ Add the increase to the original price.


🏷️ Percent Decrease / Discount Problems

Steps:

  1. Find the discount amount
    β†’ Discount = Original Γ— Percent
  2. Subtract from the original value

πŸ“˜ Used in:

  • Discounts
  • Sales
  • Price reductions

🧾 Problems with Tax or GST

  • First calculate the tax amount
  • Then add it to the original price

πŸ“Œ Tax is always calculated on the original price, not the total.


πŸ” Successive Percent Changes

  • When more than one percent change is applied:
    • Apply the first percent
    • Use the new value for the next percent
  • Do not add the percentages directly.

✏️ Use Equations When Helpful

  • Let the unknown be x
  • Write equations like:
    • Final value = Original Β± (Percent Γ— Original)

This helps in word problems.


πŸ” Check Your Answer

  • Does the answer make sense?
    • Increase β†’ final value should be greater
    • Decrease β†’ final value should be less
  • Recheck calculations to avoid small mistakes.

🧠 Common Mistakes to Avoid

❌ Adding percentages directly
❌ Forgetting to convert percent to decimal
❌ Skipping steps
❌ Using the wrong base value


⭐ Tip for Students

πŸ‘‰ Write each step clearly
πŸ‘‰ Label values (β‚Ή, %, units)
πŸ‘‰ Practice with real-life examples like shopping and bills

Learn with an example

First find the price. Write 50% as the decimal 0.50 before using it in the equation.

price=cost+mark-up

=4060+0.50*4060

=4060+2030

=6090

The price was β‚Ή6,090.

Now find the commission. Write 20% as the decimal 0.20 before using it in the equation.

commission=commission percentageΓ— sales

=0.20Γ—6090

=1218

The commission was β‚Ή1,218.

First find the original price. Write 80% as the decimal 0.80 before using it in the equation.

price=cost+mark-up

=100+0.80Γ—100

=100+80

=180

The original price was β‚Ή180.

Now find the discount price. Write 5% as the decimal 0.05 before using it in the equation.

discount price=original price-discount

=180-0.50Γ—180

=180-9

=171

The discount price was β‚Ή171.

First find the discount price. Write 60% as the decimal 0.60 before using it in the equation.

discount price=original cost-discount

=5750-0.60Γ—5750

=5750-3450

=2300

The discount price was β‚Ή2,300.

Now find the commission. Write 15% as the decimal 0.15 before using it in the equation.

commission=commission percentageΓ— sales

=0.15Γ—2300

=345

The commission was β‚Ή345.

let’s practice!