Use physical items like LEGO bricks or Cheerios to show why doubling and halving works.
Cut one number in half and double the other. The answer stays the same. Example: 14 x 5 Half of 14 is 7. Double of 5 is 10. . (Much easier than 14 x 5!) Mental Math Kids Can't Resist!: Tips, Short-cut...
At a restaurant, ask them to mentally calculate the 10% or 20% tip before you look at the receipt. Use physical items like LEGO bricks or Cheerios
Making math feel like a game rather than a chore is the "secret sauce" for helping kids master numbers. When kids realize they can solve problems faster than a calculator can be turned on, their confidence skyrockets. Example: 14 x 5 Half of 14 is 7
Give the kid the "trick" and give yourself a calculator. Race to see who gets the answer first. (Let them win!)