412 * 81 +11 * 19 * 925 +537

Quadrature

412 × 81 +11 × 925 +537 × 19 = 412 × 81 +10 × 925 +925 +412 × 19 +125 × 20-125 = 412 × (81 +19 ) + (9250 +925 +2500-125) = 412 × 100 +12550 = 41200 +12550 = 53750

412 × 81 +11 × 925 +537 × 19
= 412 × 81 +11 × 925 + (412 +125) × 19
= 412 × (81 +19) +11 × (800 +125) +125 × (20-1)
= 41200 +8800 +11 × 125 +125 × 20-125
= 50000 +10 × 125 +20 × 125
= 50000 +1250 +2500
= 53750