Comparison word problems | Addition and subtraction within 20 | Early Math | Khan Academy

TL;DR

This video demonstrates how to solve math problems involving marbles and stamps.

Transcript

• [Voiceover] So they tell us that Alexander has nine marbles, Emily has five marbles. And then we're asked, how many more marbles does Alexander have than Emily? So pause the video and try to see if you could figure this out. Now let's work this out together. So let's just draw it out. Alexander has nine marbles. So we could draw his marbles. So o... Read More

Key Insights

• 🫠 Solving math problems often requires carefully reading and understanding the given information.
• 🛩️ Subtracting the smaller quantity from the larger quantity can determine the difference between them.
• 🦻 Visual representations, such as drawings or diagrams, can aid in solving math problems and understanding the concepts.
• 💨 Math problems involving quantities and differences can be approached in multiple ways.

Questions & Answers

Q: How many more marbles does Alexander have than Emily?

Alexander has four more marbles than Emily. One way to determine this is by subtracting the number of marbles Emily has (five) from the number of marbles Alexander has (nine), which gives us four.

Q: How many stamps does the lighter letter have?

The lighter letter has three stamps. This can be found by recognizing that the lighter letter has five fewer stamps than the heavier letter (which has eight stamps), resulting in three stamps.

Q: What is another way to calculate the difference in marbles between Alexander and Emily?

Another method is subtracting the number of marbles Emily has (five) from the number of marbles Alexander has (nine), resulting in four. This represents the extra marbles that Alexander has compared to Emily.

Q: How can we visually represent the difference in the number of stamps between the heavier and lighter letter?

By drawing eight stamps for the heavier letter and then subtracting five stamps from the lighter letter, we can visualize that the lighter letter has three stamps.

Summary & Key Takeaways

• The first problem involves determining how many more marbles Alexander has than Emily. Alexander has nine marbles, while Emily has five marbles, making a difference of four marbles.

• In the second problem, the heavier letter has eight stamps, and the lighter letter has five fewer stamps. By subtracting five from eight, we find that the lighter letter has three stamps.