Let’s make a number line
0. 1/5. 2/5. 3/5. 4/5. 1
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4/5 is closer to 1 so we can round it to 1.
1 8/9 can be separated into 1 + 8/9
Here is another number line
0. 1/9. 2/9. 3/9. 4/9. 5/9. 6/9. 7/9. 8/9 1
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8/9 is closer to 1, so we can round it to 1.
Now we have 1+1 = 2
The question asks us to multiply both fraction using the estimations.
So instead of,
4/5 x 1 8/9.
We use
1 x 2,
Which is =2
(So the answer is 2 or b)