Decimal Detective

About This Game

Decimal Detective turns students into mathematical sleuths solving decimal-based mysteries across the city. Each case presents a new decimal challenge - comparing prices at the grocery store, calculating distances on a map, determining the winner of a race by hundredths of a second, or figuring out the total cost of items with tax. Students progress through increasingly complex cases that build decimal understanding from identification through advanced operations. The game features five detective districts: Money Market (decimals as money), Measurement Mile (decimals in measurement), Sports Stadium (decimals in scores and times), Science Lab (decimals in data), and Percent Plaza (connecting decimals to percentages). With a magnifying glass that reveals place values, a calculator tool for checking work, and a detective notebook that builds with each solved case, Decimal Detective makes decimal operations engaging and accessible for upper elementary students.

Learning Objectives

• Read, write, and compare decimals to thousandths
• Understand place value for tenths, hundredths, and thousandths
• Add and subtract decimals to hundredths
• Multiply and divide decimals
• Connect decimal notation to fractions and percentages

How to Play

1. Choose a detective district to explore
2. Read the decimal mystery carefully
3. Use the magnifying glass to examine place values
4. Solve the decimal problem
5. Enter your answer with the decimal point in the right place
6. Submit to crack the case and earn your detective badge

Tips for Success

• Line up decimal points when adding or subtracting
• Count decimal places when multiplying decimals
• Always estimate first to check if your answer makes sense
• Remember that 0.5 = 1/2 = 50% - they are all the same amount

Skills Developed

Common Core Standards

• 4.NF.C.7 - Compare two decimals to hundredths
• 5.NBT.A.3 - Read, write, and compare decimals to thousandths
• 5.NBT.B.7 - Add, subtract, multiply, and divide decimals to hundredths