Grade 4 - Progress in Mathematics

Use Front-End Estimation

Front-end estimation is another way to estimate

decimal sums and differences.

To make a front-end estimate with decimals:


Add or subtract the nonzero front digits.


Write zeros for the other digits.


 8 3.41 
 9 .3 
0. 65


 7 1.3  4 .76 
0. 5

about
 15 0.00 about
 5 .00 about
 1. 10

Estimate the sum or the difference. Use front-end estimation.

24. 
    30.98 25.
    8.6 26.
    43.21 27.
    7.4 28.
    58.4
    
    56.44
    9.2 12.04 2.9 21.62


25. 
    0.94 30.
    0.26 31.
    23.2 32.
    48.4 33.
    74.6
    0.55
    0.77
    96.09 18.36 21.09


26. 
    8.09 35.
    6.74 36.
    81.2 37.
    50.09 38.
    59.5
    
    8.9 1.53 27.35
    97.79 24.07

Use front-end estimation.

39. Maria jogged 97.5 miles. Audrey jogged 79.37 miles.
    About how many more miles did Maria jog than Audrey?

Find the quotient.

40. 2
    $ 37 .3 2  41. 4
    $ 10 .4 0  42. 9
    $ 2 .7 9  43. 8
    $ 64 .1 6 


41. 24
    $ 87 .6 0  45. 53
    $ 57 .2 4  46. 39
    $ 82 .2 9  47. 42
    $ 41 .1 6 

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