Example: 2-digit times 2-digit | Multiplication and division | Arithmetic | Khan Academy

TL;DR

Learn how to compute 23 times 44 using the traditional multiplication method with carrying.

Transcript

Compute 23 times 44. And maybe the hardest part of this problem, or maybe the first hard part, is to recognize that that dot even means multiplication. This could have also been written as 23 times 44, or they could have written it as 23 in parentheses times 44, so you just put the two parentheses next to each other. That also implies multiplicatio... Read More

Key Insights

• 🫥 The dot in multiplication signifies the operation, and it can be written in different ways, such as parentheses or without any symbol.
• 🥇 When multiplying by a digit in the tens or higher place, zeroes may be added to maintain proper place value.
• ✖️ The traditional multiplication method involves multiplying each digit and carrying over if necessary.
• 🥇 Place value understanding is crucial when performing multiplication.
• 🪜 The overall process involves multiplying digits, carrying over, and adding the products to obtain the final result.
• ✖️ The steps in multiplication can be visualized vertically to simplify the calculation.
• 🍹 The sum of the products gives the final result of the multiplication.

Questions & Answers

Q: How do you recognize the multiplication symbol in the equation?

In the equation 23 x 44, the dot between the numbers signifies multiplication. It could also be represented as 23(44) or (23)(44), which imply multiplication as well.

Q: How do you start multiplying the digits?

To multiply 4 (ones place) by 23, you multiply 3 (from 23) by 4, which equals 12. Write down 2 as the ones place digit and carry over 1 to the tens place.

Q: Why is a zero added when multiplying by the tens place digit?

When multiplying by a tens place digit, such as 40, a zero is added to maintain correct place value. This ensures that the product of 4 times 23 is added correctly.

Q: How do you calculate the product of 4 times 23?

Multiply 4 by 3, which equals 12. Write down 2 as the tens place digit and carry over 1 to the hundreds place. Then, multiply 4 by 2, which equals 8, and add the carried over 1 to get 9.

Summary & Key Takeaways

• The dot in the equation 23 x 44 represents multiplication.

• Multiplication is done vertically, with the numbers lined up.

• The process involves multiplying each digit and carrying over if necessary.