Answer:
7,200
Explanation:
So you have 77 x 87
Round 77 ( look at the ones place, is it 5 and up? In this scenario it is. So you want to go up one in the tens place and replace the 7 with a 0 in the ones place) Which looks like this: 80
Do the same thing with the number 87
You should get 90
So now you have 80 x 90
If you want to solve without a calculator you should know your multiplication such as 4 x 5 which is obviously 20
In this scenario remove the zeros
8
x 9
___
72
Now add the total number of zeros from both numbers which there are 2 zeros in total. Add the 2 zeros to the total of 8 x 9.
And you should get 7,200
Hope this makes sense!