Free Tips to do Mental Math Questions Easy in 2011- Part 4
This is my fourth blog of tips to do well in math problems. Please find some tips to do math questions easy. These tricks are easy to remember to do all math calculations: Blog-1-Tips to do Mental Math Questions Easy Blog 2-Free Tips to do Mental Math Questions Easy in 2011 Blog 3-Mental Math Questions Easy 19. Multiplying by a power of 2 To multiply a number by 2, 4, 8, 16, 32, or some other power of 2 just keep doubling the product as many times as necessary. If you want to multiply by 16 then double the number 4 times since 16 = 2x2x2x2. 15x16: 15x2 = 30. 30x2 = 60. 60x2 = 120. 120x2 = 240. 23x8: 23x2 = 46. 46x2 = 92. 92x2 = 184. 54x8: 54x2 = 108. 108x2 = 216. 216x2 = 432. 20. Squaring 2-digit numbers that end in 5 If a number ends in 5 then its square always ends in 25. To get the rest of the product take the left digit and multiply it by one more than itself. 35x35 ends in 25. We get the rest of the product by multiply...