This video tutorial teaches how to add decimals using the standard algorithm. It begins with an introduction to decimal addition and explains the importance of placeholders. The concept of algorithms is defined, highlighting their role in solving arithmetic problems. Common mistakes, such as misaligning decimals, are addressed. The video demonstrates the use of estimation to check the reasonableness of answers. A detailed, step-by-step application of the standard algorithm is provided, followed by a conclusion summarizing the key points.

What is the role of a placeholder in a decimal number?

• To maintain the value of the number

• To indicate the end of a number

• To change the value of the number

• To make the number larger

Why is it important to align decimal points when adding decimals?

• To avoid carrying over numbers

• To simplify the calculation

• To ensure correct addition of place values

• To make the numbers look neat

What is the first step in the standard algorithm for adding decimals?

• Estimate the sum

• Align the decimal points

• Add the smallest place value

• Check the sum with estimation

In the example provided, what is the estimated sum of 3, 4.25, and 3.9?

• 11

• 10

• 13

• 12

What is the final answer when adding 3, 4.25, and 3.9 using the standard algorithm?

• 12.15

• 11.15

• 11.05

• 10.15