Estimate the following product to the nearest thousands:  5281 x 3491.

To estimate the product, first, we need to estimate the numbers individually to the nearest thousands.

To round off a number to the nearest thousands, 

If the digit at the hundreds place is less than 5 then the hundreds and one's digits become zero and the thousands digit remains the same.
 

If the digit at the hundreds place is greater than or equal to 5 then the hundreds and one's digit becomes zero and the thousands digit increase by 1.

Rounded off 5281 = 5000

Rounded off 3491 = 3000

So the product after rounding off each number to the nearest thousands we get,

 Rounded off 5281 x 3491 to thousands: 5,000 x 3,000 = 1,50,00,000