Adding and subtracting on number line word problems | Early Math | Khan Academy

TL;DR

Ying Ying ran a total of 39 laps, and the red ant army has 93 ants left.

Transcript

• All right, so we have Ying Ying had run a total of 30 laps for Running Class, or Running Club, I should say. So Ying Ying ran a total of 30 laps. Then, Ying Ying ran four more laps before school. So she ran four more laps before school. Three more laps at lunch, three more laps at lunch. And two more laps at recess. Ying Ying's doing a lot of run... Read More

Key Insights

• 👏 Ying Ying ran a total of 39 laps, showing steady progress.
• 🫥 Using a number line can be an effective tool for visualizing and calculating quantities.
• 🏮 The red ant army experienced a significant reduction in the number of ants due to various factors.

Questions & Answers

Q: How many laps did Ying Ying run in total?

Ying Ying ran a total of 39 laps, including the initial 30 and the additional laps before school, at lunch, and during recess.

Q: How was the total number of laps determined using a number line?

By starting at 30 laps and adding 4 for laps before school, 3 for laps at lunch, and 2 for laps at recess, the number line showed that Ying Ying ran a total of 39 laps.

Q: How many ants did the red ant army start with?

The red ant army started with 100 marching ants.

Q: How many ants are left in the red ant army?

After losing 3 ants down a hole, having 3 ants eaten by a bird, and 1 ant blowing away, the red ant army has 93 ants left.

Summary & Key Takeaways

• Ying Ying ran 30 laps for Running Club, then ran an additional 4 laps before school, 3 laps at lunch, and 2 laps at recess.

• Using a number line, it was determined that Ying Ying ran a total of 39 laps.

• The red ant army started with 100 ants, lost 3 ants down a hole, had 3 ants eaten by a bird, and 1 ant blew away.

• Another number line exercise determined that the red ant army has 93 ants left.