Separate+Change+Unknown

Separate Change Uknown

Connie had 13 marbles. She gave some to Juan. Now she has 5 marbles left. How many marbles did Connie give to Juan?

Direct Modeling: (Separate to) 13 - ? = 5 13 - 8 = 5

media type="file" key="Movie 1.mov" width="300" height="300"

Modeling: (Separate From) 13 - 5 = ? 13 - 5 = 8 media type="file" key="Movie 2.mov" width="300" height="300"

Modeling: (Join to) 5 + ? = 13 5 + 8 = 13 media type="file" key="Movie 3.mov" width="300" height="300"

Counting: (Count down to) 13 - ? = 5

(Count down from) 13 - 5 = ?

(Count up to) 5 + ? = 13 media type="file" key="Movie 4.mov"

Facts:

Student is unsure of the fact 13 - ? = 5.

Student knows that 10 - 5 = 5

The student the knows he needs to add 3 to the 5 (3 + 5), and finds that the answer is 8.