GUIDE深度 · Deep dive
Mental Math Strategies
Fast mental math is about splitting numbers into easy parts: round up for addition, subtract tens first, split multiplication into tens plus ones, and turn division into multiplication. Accuracy first, then speed.
Add and subtract
37+48: 37+50-2=85.
83-47: 83-40-7=36.
Multiply and divide
14x6: 10x6 + 4x6 = 84.
72/8: think 8x9=72.
Practice one strategy at a time, say the intermediate step out loud, and only increase speed after three accurate sessions.
FAQ
How long per day?
Five to ten minutes; accuracy before speed.
What if I miss one?
Choose Again; it returns tomorrow, and stretch the interval after three correct recalls.