Most children can easily do these mild types of riddles by themselves, without my help or the help of the base ten blocks:
I have 4 tens and 8 ones. Who am I?
I am 36. How many tens do I have?
If you put 3 more tens with me, I would be 46. Who am I?
If you take away 1 ten, I would be 78. Who am I?
Then, they get more and more challenging. We work these out in small groups or with me leading the whole group. Base ten blocks really help the students visualize what is happening:
I am 56. I have 26 ones. How many tens do I have?
If you put 4 more tens with me, I would be 125. Who am I?
If you take away 5 tens, I would be 94. Who am I?
I am 452. I have 25 tens. How many hundreds do I have?
I have 18 ones. I am between 130 and 140. How many tens do I have?
These types of riddles are great practice for developing true number sense. Students find it fun to manipulate and play with numbers in this way, as long as it is kept low-stakes and light. Need to entertain your children while waiting for your food at a restaurant? Try making some of the base-10 riddles for each other!