Swapping numbers for lines can make the hardest mental arithmetic seem easy peasy and this is how to do it What are you like at multiplications? Chances are if you're a mere mortal 2, 5s and 10s won't ...
What are you like at multiplications? Chances are if you're a mere mortal 2, 5s and 10s won't seem too taxing. But when it comes to figuring out what 42x21 is, you may wish somebody had shown you the ...