In this Grade 4 Saxon Math Intermediate 4 lesson, students learn to add and subtract decimal numbers that have different numbers of decimal places by aligning decimal points and treating empty place values as zeros. The lesson reinforces understanding of place value from hundreds to hundredths, helping students identify digits in the tenths and hundredths positions. Practice problems guide students through operations such as 3.75 + 12.5 + 2.47 and 4.25 − 2.5 using the standard vertical algorithm.
Section 1
📘 Adding and Subtracting Decimal Numbers, Part 2
We line up the decimal points to ensure that we are adding and subtracting digits with the same place value.
Next, you’ll apply this rule to add and subtract decimal numbers with varying lengths, treating empty places as zeros.
Section 2
Place value power-up
The decimal point is your guide for finding the value of each place. To the left is the ones place, then tens, and hundreds. To the right of the decimal point, you find the tenths place which represents , and then the hundredths place which represents . Lining up decimals ensures you're working with matching place values.
In the number , the digit is in the tenths place.
In the number , the digit is in the hundredths place.
In the number , the digit is in the ones place.
Picture the decimal point as your team's center. To the left are the big-point players like ones and tens. To the right are the fractional-point specialists like tenths and hundredths. Know their positions!
Section 3
Decimal addition alignment
To add decimal numbers, you must focus on lining up the decimal points, not the last digits. This process ensures you are adding digits with the same place value, like tenths to tenths and hundredths to hundredths. If a number has fewer decimal places, you should treat any empty place to the right as a zero.
. Add a placeholder zero to 2.6 to align the hundredths place.
. Align the decimals by adding a zero to 12.1 before you sum.
. Treat the empty hundredths place in 0.5 as a zero and add.
Adding decimals is like a conga line where all decimal points must line up perfectly! This keeps your place values straight. Treat empty spaces as zeros so no number gets left behind.
Section 4
Decimal subtraction showdown
When you subtract decimal numbers, the most important step is to line up the decimal points correctly. This guarantees you are subtracting digits of the same place value from each other. Just like in addition, you must treat any empty place in the number you are subtracting as a zero by adding a placeholder.
. Line up the decimals and add a zero to 2.5.
. Align decimal points and fill the empty hundredths place with a zero.
. Add a zero to 4.2 to subtract from the hundredths place.
Subtracting decimals is a showdown where decimal points must align. This ensures a fair fight between matching place values. Add zeros to empty spots for backup so you can borrow when needed!
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Section 1
📘 Adding and Subtracting Decimal Numbers, Part 2
We line up the decimal points to ensure that we are adding and subtracting digits with the same place value.
Next, you’ll apply this rule to add and subtract decimal numbers with varying lengths, treating empty places as zeros.
Section 2
Place value power-up
The decimal point is your guide for finding the value of each place. To the left is the ones place, then tens, and hundreds. To the right of the decimal point, you find the tenths place which represents , and then the hundredths place which represents . Lining up decimals ensures you're working with matching place values.
In the number , the digit is in the tenths place.
In the number , the digit is in the hundredths place.
In the number , the digit is in the ones place.
Picture the decimal point as your team's center. To the left are the big-point players like ones and tens. To the right are the fractional-point specialists like tenths and hundredths. Know their positions!
Section 3
Decimal addition alignment
To add decimal numbers, you must focus on lining up the decimal points, not the last digits. This process ensures you are adding digits with the same place value, like tenths to tenths and hundredths to hundredths. If a number has fewer decimal places, you should treat any empty place to the right as a zero.
. Add a placeholder zero to 2.6 to align the hundredths place.
. Align the decimals by adding a zero to 12.1 before you sum.
. Treat the empty hundredths place in 0.5 as a zero and add.
Adding decimals is like a conga line where all decimal points must line up perfectly! This keeps your place values straight. Treat empty spaces as zeros so no number gets left behind.
Section 4
Decimal subtraction showdown
When you subtract decimal numbers, the most important step is to line up the decimal points correctly. This guarantees you are subtracting digits of the same place value from each other. Just like in addition, you must treat any empty place in the number you are subtracting as a zero by adding a placeholder.
. Line up the decimals and add a zero to 2.5.
. Align decimal points and fill the empty hundredths place with a zero.
. Add a zero to 4.2 to subtract from the hundredths place.
Subtracting decimals is a showdown where decimal points must align. This ensures a fair fight between matching place values. Add zeros to empty spots for backup so you can borrow when needed!
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter