please help me, urgent

Question

use benchmarks to estimate each sum or difference

1. 4/5 + 8/9

2. 17/18 - 3/7

use rounding or compatible numbers to estimate each product or quotient

3. 5x2 3/5

4. 25 7/8 / 2 8/9

 

 

Answer 1

Hi Jamie,

 

1.  Both fractions are fairly close to 1, so the the problem becomes, approximately, 1 + 1 = 2

 

2.  The first fraction is just under 1 and the second fraction is just under 1/2, so the problem becomes, approximately, 1 - 1/2 which is 1/2. 

 

3.  Great time to use the Distributive Property.  The problem can be converted from 5 * 2  3/5 to 5*2 + 5* 3/5, which is 10 + 3 which is 13.

 

4.  Great time to estimate.  25  7/8 is almost 26 and 2  8/9 is almost 3, so the problem becomes 26 * 3, which becomes a great time to use the Distributive Property, 3 * 26 = 3*20 + 3*6 = 60 + 18 = 78.

 

Hope this helps,

Mary Ann