2.04 Subtraction with regrouping
Are you ready?
When we add numbers together, place value is really important. Do you remember how to add numbers with $3$3 or more digits together?
Let's find the value of $205+305$205+305, by partitioning the numbers.
Fill in the box with the missing number.
$205=200+\editable{}$205=200+
Fill in the box with the missing number.
$305=\editable{}+5$305=+5
Find the value of $205+305$205+305.
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Another word that we can use to describe the ones place is 'units'.
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You might notice that sometimes the standard algorithm is called the 'vertical algorithm'. Let's think about why. When we use the standard algorithm, we line our numbers up in 'vertical' place value columns.
Learn
When we subtract, we may need to regroup, or trade, some of our numbers. This video shows how we can do that, so that we can subtract another number. Let's take a look.
Apply
Question 1
Find the value of $595-229$595−229.
Learn
This time we have numbers with more digits, and the video shows how we can trade, or regroup, thousands to help us subtract in the hundreds place.
Apply
Question 2
Find the value of $8772-3853$8772−3853.
If we don't have enough to subtract, we can regroup from the next place to the left.
