Question

How do I get 323,584 for 512 times 632

Answer 1

You can write rewrite 632 as follows:

$632 = 2 + 3\times 10 + 6 \times 100$

So, you have

$512 \times 632 = 512 \times (2 + 3\times 10 + 6 \times 100)$

Which you can distribute as

$512 \times 2 + 512 \times 3\times 10 + 512 \times 6 \times 100$

You can easily compute

$512 \times 2 = 1024,\quad 512 \times 3 = 1536,\quad 512\times 6 = 3072$

So,

$512 \times 2 + 512 \times 3\times 10 + 512 \times 6 \times 100 = 1024 + 15360 + 307200$

which gives 323584