LI: How to subtract decimals using algorithims
This week for today we got to make a DLO about how to subtract decimals using algorithims, Subtracting decimals using the standard algorithm is all about precision and alignment. The golden rule is to align the decimal points vertically, which automatically lines up your place values (tenths, hundredths, etc.). Step 1: Set Up the Problem Write the numbers vertically so that the decimal points line up directly on top of each other. The number you are subtracting from goes on top, and the number you are subtracting goes on the bottom. Step 2: (The Placeholder Step)If the numbers do not have the same number of decimal places, fill the empty spaces with zeros.
This changes the value of the numbers, but it keeps them mathematically comparable and makes borrowing much easier to visualize. Step 3: Subtract from Right to Left Begin subtracting the digits in the furthest right column, just like you would with whole numbers. Step 4: Drop the Decimal Point. Bring the decimal point straight down into your answer. Make sure it aligns perfectly with the decimal points in the problem above it. Step 5: Complete the Left Columns Finish subtracting the digits to the left of the decimal point. The Technique: Borrowing (Regrouping) Sometimes, the digit on the bottom is larger than the digit on top. When this happens, you must borrow from the next digit to the left.