784 + 398 simple operation It's 784 + 398. Don't make a mistake. Add

784 + 398 simple operation It's 784 + 398. Don't make a mistake. Add

784+398
=784+(400-2)
=784+400-2
=1184-2
=1182

Simple calculation: 654 * 322-655 * 321

654*322-655*321
=(655-1)*(321+1)-655*321
=655*321+655-321-1-655*321
=655-321-1
=333

213 △ 9 / 212 [simple calculation]

213÷9/212=213×212/9=71×212=15052
This problem should be multiplication, that is 213 × 9 / 212 = (212 + 1) × 9 / 212 = 212 × 9 / 212 + 1 × 9 / 212 = 9 + 9 / 212 = 9 and 212 numerator 9

Simple calculation of 48 × 213-13
emergency

48×213-13
=（50-2）x213-13
=50x213-2x213-13
=10650-426-13
=10211
48×213-13
=48x200+48x13-13
=9600+47x13
=9600+（50-3）x13
=9600+50x13-3x13
=9600+650-39
=10211