You have the following product:
27 x 8
To estimate the product by rounding 27 to 25, you consider that 25 x 8 is the same as adding 25 eight times.
Then, you have:
25 x 8 = 25 + 25 + 25 + 25 + 25 +25 + 25 +25
25 x 8 = 50 + 50 + 50 + 50 each pair of 25's add up 50
25 x 8 = 100 + 100 each pair of 50's add up 100
25 x 8 = 200
Hence, an estimation of the given product is 200, by considering 27 rounded to 25.
