Use physical items like LEGO bricks or Cheerios to show why doubling and halving works.
If the middle sum is 10 or more (like 87 x 11), just carry the "1" to the first digit! 3. The "Doubling and Halving" Method Mental Math Kids Can't Resist!: Tips, Short-cut...
This is arguably the coolest-looking trick in mental math. It works for any two-digit number multiplied by 11. Use physical items like LEGO bricks or Cheerios
This is how our brains naturally read, so it feels more intuitive than the "stacking" method. 5. Squaring Numbers Ending in 5 This one makes kids look like absolute geniuses. The Trick: To square a number like 25, 35, or 75: The answer always ends in 25. The "Doubling and Halving" Method This is arguably
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!)