Give the kid the "trick" and give yourself a calculator. Race to see who gets the answer first. (Let them win!)
Round one number to the nearest ten to make it "friendly," solve the problem, and then adjust. Example: For 38 + 25 , turn 38 into 40 (by adding 2). The Math: . Now, take away that extra 2 you added earlier. Mental Math Kids Can't Resist!: Tips, Short-cut...
It’s great for any problem involving a 5 or an even number. 4. "Front-End" Addition Give the kid the "trick" and give yourself a calculator
This is arguably the coolest-looking trick in mental math. It works for any two-digit number multiplied by 11. Example: For 38 + 25 , turn 38 into 40 (by adding 2)
Take the first digit and multiply it by the "next" number up. 65 x 65 The end is 25 . The first digit is 6. The next number up is 7. Put them together: 4,225 . How to Make it "Irresistible"