Write an addition story for two 3-digit numbers

Josie has 125 trading cards. Belle has 240 trading cards. How many cards do they have all together?

Sabrina has 280 trading cards, but Mariana has 300 trading cards. How many cards do they have in all?

Isabelle has 180 flowers. Her mother has 286 flowers. How many flowers do they have in all?

Sure! Here's an addition story for two 3-digit numbers:

Once upon a time, there were two friends named Alex and Ben. Alex had 3 different types of toys, and each type had 145 toys. Ben had 2 different types of toys, and each type had 245 toys. They decided to combine their toy collections to see how many they had in total.

To find the sum of their toy collections, we need to add the number of toys Alex has with the number of toys Ben has.

To do this, we start by adding the ones place, which is the rightmost digit. In this case, we add 5 (from 145) with 5 (from 245), which gives us 10. Since 10 is a two-digit number, we carry over the tens place to the next column.

Next, we add the tens place, which is the middle digit. We add 4 (from 145) with 4 (from 245), plus the carry-over of 1 from the previous step. This gives us 9. Again, since 9 is a two-digit number, we carry over the hundreds place to the next column.

Finally, we add the hundreds place, which is the leftmost digit. We add 1 (from 145) with 2 (from 245), plus the carry-over of 1 from the previous step. This gives us 4.

So, the sum of Alex's and Ben's toy collections is 495.

In summary, Alex had 145 toys and Ben had 245 toys. When we added them together, we got a total of 495 toys.