Rounding off 71 to the nearest 10 will be 70
rounding off 98 to the nearest 10 will be 100
Estimating the product will be 70 * 100 ≈ 7000
Now lets do the actual calculation :
71 x 98 =6958
This is much nearer to 7000
Extra notes: any number below 5 , go down to the nearest 10.
Example : 71 ≈70
Any number that is 5 or higher, go up to the nearest 10
Example 98 ≈100