Please give a detailed answer to the simple math calculation in Grade 6 of primary school, thank you! (216:44:0) 11 by 12 by 13-12 by 13-260

Please give a detailed answer to the simple math calculation in Grade 6 of primary school, thank you! (216:44:0) 11 by 12 by 13-12 by 13-260

11×12×13-12×13-260
=11×（12×13）-1×（12×13）-260
=（11-1）×（12×13）-260
=10×156-260
=1560-260
=1300

How to quickly calculate such a problem
Now there are activities in the soda shop! Four soda bottles can be exchanged for one! Xiaoming buys ten soda bottles! At the end, he can drink twelve soda bottles! Suppose Xiaoming buys several hundred bottles, how can he quickly calculate how many more soda bottles Xiaoming can get? If Xiaoming wants to drink one thousand soda bottles at the end, how many soda bottles can he drink?

This problem involves three units: empty bottle, soda, soda with bottle,
You can trade four soda bottles for one
==1 soda water = 3 empty bottles = 3 / 4 soda water with bottles
If Xiao Ming can drink x bottles at the end of the day
X bottles of soda refers to x bottles of soda. How many bottles of soda do you buy refers to the bottles of soda with you,
X * 3 / 4 = [3x / 4] ([] is full rounding)

How to calculate the mathematical calculator, if 5 * 8 + 6 * 7 such problems

Advanced calculator can use brackets, this is very simple
Ordinary calculator will use memory function, that is, M + and so on
First calculate 5 * 8, save the result, then calculate 6 * 7, and add it to the saved value

Simple calculation in mathematics, simple on-line calculation, etc
1/3×2+2/3÷1/2
4×0.8×12.5×0.25
29×17/28

1/3×2+2/3÷1/2
=1/3×2+2/3×2
=2×(1/3+2/3)
=2
4×0.8×12.5×0.25
=4×0.25×0.8×12.5
=1×10
=10
29×17/28
=（28+1）×17/28
=28×17/28+17/28
=17+17/28
=17 and 17 / 28