Decimal Operations
Year 5 students add, subtract, multiply, and divide decimal numbers to two decimal places, applying strategies for accuracy and estimation.
What You Need to Know
Key Concept Diagram
Adding and subtracting decimals requires lining up the decimal point so place values are aligned
Multiplying a decimal by 10 moves the digits one place to the left (value increases)
Dividing a decimal by 10 moves the digits one place to the right (value decreases)
Estimating with decimals uses rounding to the nearest whole number first
Key Vocabulary
Decimal point
The dot that separates the whole number part from the fractional part
Tenths
The first digit after the decimal point; one tenth equals 0.1
Hundredths
The second digit after the decimal point; one hundredth equals 0.01
Estimate
A rounded approximation used to check the reasonableness of a calculation
Knowledge Check
Select the correct answer for each question. Click "Check Answer" to see if you are right.
Question 1
3.47 + 2.6 = ?
Question 2
7.5 × 10 = ?
Question 3
9.36 − 4.7 = ?
Key Concepts Summary
- ●Adding and subtracting decimals requires lining up the decimal point so place values are aligned
- ●Multiplying a decimal by 10 moves the digits one place to the left (value increases)
- ●Dividing a decimal by 10 moves the digits one place to the right (value decreases)
- ●Estimating with decimals uses rounding to the nearest whole number first