Section 1
Adding Decimals Using Partial Sums
Property
To add decimals using partial sums, add the values in each place value column separately. The total sum is the sum of these partial sums.
In this Grade 5 enVision Mathematics lesson, students learn how to add decimals using place value strategies, partial sums, and properties of operations including the Commutative and Associative Properties. The lesson connects decimal addition to whole number addition by aligning addends by place value and lining up decimal points. Students practice finding sums with tenths and hundredths in real-world contexts such as relay race times and distances.
Section 1
Adding Decimals Using Partial Sums
To add decimals using partial sums, add the values in each place value column separately. The total sum is the sum of these partial sums.
Section 2
Using Decomposition to Add Decimals
Decomposition breaks numbers into their place value parts to simplify addition. When adding a whole number and a decimal, the Associative Property can be used to group the whole numbers first: , where and are whole numbers and is the decimal part.
Expand to review the lesson summary and core properties.
Section 1
Adding Decimals Using Partial Sums
To add decimals using partial sums, add the values in each place value column separately. The total sum is the sum of these partial sums.
Section 2
Using Decomposition to Add Decimals
Decomposition breaks numbers into their place value parts to simplify addition. When adding a whole number and a decimal, the Associative Property can be used to group the whole numbers first: , where and are whole numbers and is the decimal part.