<s>[INST] reverse three digit subtraction I cannot get this. How does it work? Like what is the concept in this?
Imagine $895 - 598$:


*

*Step 1. $8 - 5 = 3$    (I got $8$ and $5$ from the hundreths place in the numbers I am subtracting)

*Step 2. $3 × 100 = 300$  ($100$ is because $8$ and $5$ were originally from the hundreths)

*Step 3. $300 - 3 = 297$ (Subtract the answer from step 2 from the answer from step 1.)

*Final result. $297$ is the answer to $895 - 598$.

 [/INST] Simply,
$$895-598=\left(8\times10^2+9\times10^1+5\times10^0\right)-\left(5\times10^2+9\times10^1+8\times10^0\right)=\left(8\times10^2-5\times10^2\right)+\left(9\times10^1-9\times10^1\right)+\left(5\times10^0-8\times10^0\right)=3\times10^2+0\times10^1+\left(-3\times10^0\right)=300-3=297$$
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