Bruce Moody Observation of Me

On Thursday Bruce observed me teach a maths group this lesson using some of what he has taught us. I wanted to use money as the 10 because it is easier to count in set 10's. I had done a lot of work around place value with this group so wanted to see if they could add and subtract using their place value knowledge in 10's. 

https://nzmaths.co.nz/resource/adding-tens

Resources: Mini whiteboards and pens, notes and coins, md book and pens.
On your whiteboards:
How much is the 2 worth in 24? The 4?   
How much is the 1 worth in 10?
1. if I had saved $24 to spend at my favourite shop Kmart and my Mum gave me $10 more to spend, how much do I spend at Kmart?
Show me 24 using the money (10’s and 1 materials)
Show me 10 using the money
How much do I spend?
So because 2 + 1 = 3, then 2 tens + 1 ten is 3 tens so 24+ 10 must by $34
2. If I found $20 on the floor at Kmart and then I found another $34, how much money did I find? 
Show me 20 using the money (10’s and 1 materials)
Show me 34 using the money
How much do I spend?
40+27=, 21+50= , 340 + 20=
3. I have some money in my pocket. I lose $40 and now I have just $10. How much was in my pocket to start with?
4. I had $52 and I lost $20 on the ground, how much do I have left to spend?

Bruce's notes: 

The lesson went well. A few pointers Bruce suggested was not to use the word "Count" when I should say "Tell me how many". I also missed a step when moving from changing a single 10. I missed changing multiple 10's like 52+20 and went straight to a 2 step problem 52+24.   He also suggested I do NOT spread the money out in front of the students, instead keep them in a stack with only the top note visible (they have to imagine the rest rather than tempting them to count it).