$$32$$ in the red box represents $$20 \times 16 = 320$$, and the product should be $$320 +144 = 464$$. 
When calculating $$16\times 29$$, which of the following choices is correct? 
* $$144$$ in the blue box represents $$9\times 16$$. 
* $$32$$ in the red box represents $$2\times 16$$. 
* The product is $$32+144 =176$$. 
* There is no regrouping in the calculation. 