Dividing Decimals Using Common Units
Dividing decimals using common units is a Grade 5 math skill in enVision Mathematics, Chapter 6: Use Models and Strategies to Divide Decimals. When both the dividend and divisor share the same decimal unit (e.g., both in tenths or both in hundredths), students can divide the numerals as whole numbers. For example, 8 tenths divided by 2 tenths = 8 / 2 = 4.
Key Concepts
When dividing numbers with the same decimal unit, you can divide them as if they were whole numbers.
$$8 \text{ tenths} \div 2 \text{ tenths} = 8 \div 2 = 4$$ $$75 \text{ hundredths} \div 5 \text{ hundredths} = 75 \div 5 = 15$$.
Common Questions
How do you divide decimals that have the same decimal unit?
When both numbers are in the same unit (like tenths), divide the digit parts as whole numbers and the units cancel. For example, 0.8 / 0.2 = 8 tenths / 2 tenths = 4.
What is 0.75 / 0.05 using common units?
Both are in hundredths: 75 hundredths / 5 hundredths = 75 / 5 = 15.
Why do decimal units cancel when dividing like-unit decimals?
Just as 8 apples / 2 apples = 4, dividing equal units leaves a dimensionless quotient. The unit labels cancel and you get a whole number result.
Where is dividing decimals by common units taught in enVision Grade 5?
Chapter 6: Use Models and Strategies to Divide Decimals in enVision Mathematics, Grade 5.
Does this method work when the dividends have different decimal units?
No. When units differ, you first need to convert both to the same unit or use a standard algorithm for decimal division.