What is 3/4ths estimated by 1 and 3/8

Conversion: 3 3/8 = 3 · 8 + 38 = 278Subtract: 12 - 278 = 1 · 42 · 4 - 278 = 48 - 278 = 4 - 278 = -238
The common denominator you can calculate as the least common multiple of the both denominators - LCM(2, 8) = 8Multiple: 13 * (-238) = 1 · (-23)3 · 8 = -2324
Multiply both numerators and denominators. Result fraction keep to lowest possible denominator GCD( -23, 24)