Simple calculation of 138 times 99

Simple calculation of 138 times 99

138*99
=138*（100-1）
=13800-138
=13662

How to calculate easily 1999 * 99 + 1999

Extract common divisor 1999
Original formula = 1999 * (99 + 1)
=1999*100
=199900

Simple calculation: 302 × 99 + 138 = ==

302×99+138
=302*(100-1)+138
=30200-302+138
=30338-302
=30036

Simple calculation of 5.6 * 69.32 + 138.64 * 0.05 + 693.4 * 0.43

= 5.6*69.32 + 2*0.05*69.32 + 69.32*10*0.43 + 0.2*0.43
= 5.7*69.32+4.3*69.32+0.086
= 10*69.32 + 0.086
= 693.2 +0.086
= 693.286

60% 69.32% 138.64% 0.05% 693.2% 0.43

5.60*69.32+138.64*0.05+693.2*0.43
=5.60*69.32+69.32*2*0.05+69.32*10*0.43
=5.60*69.32+69.32*0.1+69.32*4.3
=69.32*（5.60+0.1+4.3）
=69.32*10
=693.2

Simple algorithm of 5.6 * 69.32 + 138.64 * 0.05 + 693.2 * 0.43

5.6*69.32+138.64*0.05+693.2*0.43
=5.6*69.32+6.932+693.2*0.43
=56x6.932+6.932+6.932x43
=6.932x(56+43+1)
=6.932x100
=693.2

Main process of 5.6x69.32 + 138.64x0.05 + 693.2x0.43 simple calculation and writing

5.6X69.32+138.64X0.05+693.2X0.43
=5.6×69.32+69.32×4.3+138.64×0.05
=(5.6+4.3)×69.32+69.32×2×0.05
=10×69.32+69.32+0.1
=693.2+6.932
=693.2+6.8+0.132
=700+0.132
=700.132

（1）1-12×{1-13×[1-14×（1-15）]}      （2）5.6×69.32+138.64×2.2（3）138×114+23.3×（2-75%）-125%×38+（1+0.25）×28.7．

（1）1-12×{1-13×[1-14×（1-15）]}，=1-12×{1-13×[1-14×45]}，=1-12×{1-13×[1-15]}，=1-12×{1-13×45}，=1-12×{1-415}，=1-12×1115，=1-1130，=1930；（2）5.6×69.32+138.64×2.2，=5.6×69.32+（69.32×2）×2.2，=5.6×69.32+69.32×4.4，=（5.6+4.4）×69.32，=10×69.32，=693.2；（3）138×114+23.3×（2-75%）-125%×38+（ 1+0.25）×28.7，=138×1.25+23.3×1.25-1.25×38+1.25×28.7，=（138+23.3-38+28.7）×1.25，=[（138-38）+（23.3+28.7）]×1.25，=[100+52]×1.25，=152×1.25，=190．

The number of casual wear is four times of that of professional wear, with 315 yuan for each casual wear and% for professional wear
The number of casual wear is four times that of professional wear, 315 yuan for casual wear and 210 yuan for professional wear. How much is the average number of new clothes? Quick!

(315 × 4 + 210) / (4 + 1) = 294 yuan

Lili counted the household consumption of the whole family last year: Food accounted for 37% of the total expenditure, education accounted for 28% of the total expenditure, and education was 1800 yuan less than food
Lili's family spent () yuan last year

The total expenditure of the whole family last year was x yuan
37%X-28%X=1800
9%X=1800,
X=20000 .
A: the total expenditure of the Lili family last year was (20000) yuan