Word Problems to Regroup

During the past week, the students have been learning about tens and ones. Today, I gave them a word problem hoping that some of them would stumble upon regrouping (exchanging 10 units for one rod). The problem that I ran into was that I made the word problem too easy. Most of them answered the word problem in their head, and just used a rod and units to make what they thought I wanted to see. Tomorrow, the word problem will be more challenging... one they cannot solve in their head. 

Some of the students did use the tools to explain their answer in a different way than I would have expected. I found that the lesson did teach me what most of my kids know, and what I need to do to help guide them to a more complete understanding of regrouping. The problem had to do with adding 6 and 9. Here are some pictures: 

This is an example of a student showing me what they thought I wanted to see. She knew the answer, but was trying to show me how she got the answer. I asked her to look at her problem again to see if it made sense.

I LOVE this one! He didn't necessarily regroup to solve the problem. He divided the rod into units!

He counted out 9 units on the rod, and then used a pencil to hold his place.

Next, he counted on, using the one left from the rod and five units to make six.

Finally, he counted them all and got the answer of 15.

She did almost the same thing as the boy in the previous pictures except...

She counted out six units instead and forgot about the one at the end of the rod. If she added them together without counting the unit at the end of the rod, she would have got 16. So I asked her about the unit that she had covered with her finger. She quickly took away a "free" unit and came to the correct answer of 15.

This girl used 5 rods and 9 units... So I pointed out that the problem began with six, not five...

So she changed them to six rods and nine units. She counted correctly and came to 69 (she knows how to count by 10s and 1s.) I guided her by asking her to solve the problem with only units (she put the rods away.)

She got the correct answer of 15. I asked her which answer was right, 69 or 15. She said 15. I said, "How do you know?" She told me that she shouldn't have used the rods, because they are worth 10, not 1.

Her work was very similar to the first boy and first girl, except she used a rod and counted to 6, then counted on 9 more (the rest of the rod and an additional 5 units.)