Explain how you could use mental math to find a 15% tip for a $26 restaurant bill.

10% of 26 is 2.60. Now, half of that is 1.30. Add both of them and you get 3.90. Same logic can work for a 20% tip, just double to 10%.

I'll do the first one for you. it isn't very hard at all.on number one, you have (50 × 3), which equals 150, and (3 × 3), which equals 9. after you establish that, you add 150 and 9 together. so, (150 + 9) equals 159.this means that 53 × 3 = 159.