LI: How to add decimals using algorithims

This week Group 1 have been learning about how to add decimals using algorithims. An example I could have is like 3.45 + 1.2. 1. Align the numbers vertically by the decimal point, line up the decimals so that the tenths match with tenths, and ones match with ones. This shifts the numbers to the right or left, regardless of how many digits they have. 2. Add placeholder zeros (Optional but recommended)Add zeros to the right of the decimal point so both numbers have the same number of digits. This prevents careless column mistakes. 3. Add column by column from right to left, add the numbers in the rightmost column first: (5 + 0 = 5). 4. Continue adding the remaining columns. Move to the next column to the left: (4 + 2 = 6). Then, add the ones column: (3 + 1 = 4). 5. Drop the decimal point straight down. Place a decimal point in the final answer, directly aligned with the decimal points in the numbers you added. Key Rules: Never align by the right side: Unlike whole numbers, you should never align decimal numbers to the right-hand side. Whole numbers have hidden decimals: If you are adding a whole number to a decimal (e.g., (5 + 2.75), place a decimal point at the end of the whole number and add zeros as placeholders: (5.00 + 2.75). Regrouping (Carrying): If digits in a column add up to 10 or more, write down the last digit and carry the tens digit over to the next column to the left, exactly as you would with standard addition.

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.

LI: How to multiply decimals using algorithims

This week in class, Group 1 are learning about multiplying decimal numbers. Multiplying decimals is very similar to multiplying regular whole numbers. The main difference is that after you do the multiplication, you need to figure out the correct place for the decimal point in the answer.

Here’s how it works:

First, you ignore the decimal points from the numbers you’re multiplying and just multiply the numbers as if they were whole numbers. When setting up the problem, you don’t need to line up the decimals perfectly; just focus on multiplying the digits as usual.

Next, when you start multiplying, you set everything up normally: line up the numbers to the right and multiply as if they were whole numbers. During the process, if you need to move to the next digit (like moving from ones to tens), you might add a placeholder zero to keep track of places and make sure the multiplication is accurate.

Finally, after you get the full product (the answer), you count how many decimal places there were in the original numbers you’re multiplying. For example, if one number had two decimal places and the other had one, that’s three total decimal places. Then, you take the total number of decimal places you counted and move the decimal point in your answer that many places to the left. This gives you the correct decimal answer for the multiplication.