Math
Misplacing the Decimal Point When Multiplying
Students multiply the digits correctly but put the decimal point in the wrong place.
Quick check
Why students make it
Students often line up decimal points like they do when adding or subtracting. Multiplication uses place value in a different way, so lining up decimals does not tell where the final decimal point goes.
The rule done right
Multiply as if the numbers are whole numbers, then count the total number of decimal places in the factors. Put that many decimal places in the product.
Related resources
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Math, Decimal Operations Infographic -
Decimals Infographic -
Place Value Infographic -
Math, Rounding and Estimation Infographic - Decimal Operations Reference Cheat Sheet
- Place Value & Number Sense Cheat Sheet
- Fractions, Decimals & Percents Cheat Sheet
- How to round numbers Memory Aid Cheat Sheet
- Multiplying and Dividing Decimals Worksheet
- Decimal Operations, Addition, Subtraction, Multiplication Worksheet
- Powers of 10, Multiplying and Dividing Worksheet
- Multiplication, 2-Digit by 2-Digit Worksheet
- Estimating with Compatible Numbers Worksheet
- Decimal Operations with Base-Ten Blocks Tool
- Place Value Explorer Tool
- Area Model Multiplication Studio Tool
- Decimal, Fraction & Percent Converter Tool
- Decimal Operations Mission Lab Lab
- Place Value, Decimals & Scientific Notation Lab Lab
- Classroom Store Lab Lab
- Ratio, Proportion & Percent Lab Lab