=7/8+3/8- 1/4

=7/8+ 1/8+ 1/4- 1/4

= 1+0

= 1

2.65438+3 out of 00+15 out of 0/4 out of 5.

=9/30+28/30+24/30

=(9+28+24)/30

=6 1/30

Simple calculation method:

1, complement rounding method

For the number close to integer 10 or integer 100 in the formula, it can be converted into integer 10 or integer 100, and the calculation can be simplified by adding and subtracting a number.

For example: 536-198 = 536 _ (200 _ 2) = 536 _ 200+2 = 338.

44x 10 1 = 44x( 100+ 1)= 44x 100+44 = 4444

2. Decomposition method.

In some multiplication and division formulas, a certain number can be decomposed, which makes the calculation simple.

For example: 25x1.25x32 = 25x1.25x8 = (25x4) x (1.25x8) =100x10 =100.

560÷35=560÷7÷5=80÷5= 16