How did you get “2,6001000 and 2600600”

Step 1: Recognize the breakdown for $2600 \times 1600$.

$1600 = 1000 + 600$

Step 2: Apply the distributive property.

$2600 \times 1600 = 2600 \times (1000 + 600)$

$= 2600 \times 1000 + 2600 \times 600$

Step 3: Compute $2600 \times 1000$.

Note: $2600 \times 1000 = 2{,}600 \times 1{,}000 = 2{,}600{,}000$

Step 4: Compute $2600 \times 600$.

$2600 \times 600 = 2600 \times (6 \times 100)$

$= (2600 \times 6) \times 100$

$2600 \times 6 = (2000 \times 6) + (600 \times 6)$

$= 12{,}000 + 3{,}600 = 15{,}600$

$15{,}600 \times 100 = 1{,}560{,}000$

Step 5: Add the products.

$2{,}600{,}000 + 1{,}560{,}000 = 4{,}160{,}000$

Final answer: $\boxed{4160000}$