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MATH IN DEMAND
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MATH IN DEMAND

Adding Decimals

Objectives:
  • Determine the sum of a decimal and a whole number.
  • Determine the sum of two multi-digit decimals that requires multiple regrouping.

What is a decimal?
A decimal is a number that has a whole number part separated by with a decimal point from the fractional part.
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The whole number part is in front (to the left) of the decimal point. The fractional part is behind (to the right) the decimal point.

The decimal is read as the following: Eight and ninety-seven hundredths 
What does it mean to "carry a 1"?
Also known as "regrouping", we will "carry a 1" when we are adding two one-digit numbers where the sum is greater than 9. For example, let's look at the sum of two one-digit numbers, 8 and 2. We know that 8 + 2 = 10. Since 10 is a two-digit number, we will need to "carry a 1". This means that we will write "0" below the subtraction line and then "carry the 1" to the next higher column. Let's look at an example below!

The Sum of a Decimal and a Whole Number

For our first example, we will be looking at how to determine the sum of a decimal and a whole number. We can use the following steps to determine the sum of a decimal and a whole number:
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Example #1

Your turn! Determine the sum of the following:
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Click HERE to check your answer.

The Sum of Two Decimals

For our second example, we will be looking at how to determine the sum of two decimals. We can use the following steps to determine the sum of two decimals:
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Example #2

Your turn! Determine the sum of the following:
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Click HERE to check your answer.

The Sum of Two Decimals with Multiple Regrouping

For our third example, we will be looking at how to determine the sum of two multi-digit decimals that involve regrouping more than once. We can use the following steps to determine the sum of two multi-digit decimals that requires regrouping more than once:
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Example #3

Your turn! Determine the sum of the following:
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Click HERE to check your answer.

Quiz

You will take the quiz after you have researched and taken notes.

​CLICK HERE FOR QUIZ
(C) 2025 MATH IN DEMAND​