*Estimating Percents Summary** To estimate \( 10 \% \). \( \qquad \) Mole decimal one spot left \( 10 \%-7.5 \) To estimate any multiple of \( 10 \% \) esimate \( 10 \% \) and multiply \( 10 \%-3 / 2 \) Example: to estimate \( 30 \% \). \( 10 \% \times 3 \) \( \qquad \) \( 10 \% \div 2 \) To estimate \( 5 \% \) - \( \qquad \) 1. To estimate \( 50 \% \). cut in hale cut in hasp twice To estimate \( 25 \% \) \( \qquad \) Toestimate \( 1 \% \)-Move decimal left 2 Spots \( \qquad \) To estimate \% you will pay - \( \qquad \) Subtract \( 100 \% \)-discount \%

**Estimating Percents Summary** Estimating percentages is a valuable skill for quick calculations, especially when you need a rough figure without precise computation. Below is a summary of techniques to estimate various common percentages: 1. **Estimating 1%** - **Method:** Move the decimal point two places to the left. - **Example:** - 1% of 250 = 250 → 2.50 → **\$2.50** 2. **Estimating 5%** - **Method:** Take half of 10%. - **Steps:** 1. Estimate 10% by moving the decimal one place to the left. 2. Divide that number by 2. - **Example:** - 10% of 200 = 20 - 5% ≈ 20 ÷ 2 = **\$10** 3. **Estimating 10%** - **Method:** Move the decimal point one place to the left. - **Example:** - 10% of 350 = **\$35** 4. **Estimating 15%** - **Method:** Combine 10% and 5%. - **Steps:** 1. Calculate 10%. 2. Add half of 10% (which is 5%). - **Example:** - 10% of 400 = 40 - 5% ≈ 40 ÷ 2 = 20 - 15% ≈ 40 + 20 = **\$60** 5. **Estimating Multiples of 10% (e.g., 20%, 30%, etc.)** - **Method:** Calculate 10% and multiply by the desired factor. - **Example:** - 10% of 150 = 15 - 30% ≈ 15 × 3 = **\$45** 6. **Estimating 25%** - **Method:** Take half of 50%. - **Steps:** 1. Calculate 50% (half of the total). 2. Divide that number by 2. - **Example:** - 50% of 80 = 40 - 25% ≈ 40 ÷ 2 = **\$20** 7. **Estimating 50%** - **Method:** Simply take half of the total amount. - **Example:** - 50% of 120 = **\$60** 8. **Estimating 100% minus Discount Percentage (To Find the Percentage You'll Pay)** - **Method:** Subtract the discount percentage from 100%. - **Example:** - If there's a 20% discount, you'll pay 80% of the original price. **Additional Tips:** - **Combining Estimates:** For percentages that are not straightforward (e.g., 18%), break them down into known percentages (10% + 5% + 3%) and estimate each part separately. - **Practice with Real Numbers:** Apply these methods to everyday calculations, such as discounts, tips, taxes, and interest rates, to become more comfortable with quick estimations. **Example Application:** *Calculate 25% of \$200* 1. **50% of \$200:** \$200 ÷ 2 = **\$100** 2. **25% is half of 50%:** \$100 ÷ 2 = **\$50** *Therefore, 25% of \$200 is approximately \$50.* By mastering these estimation techniques, you can perform quick and effective percentage calculations without the need for a calculator.