IN THE DIY SHOP

This astonishing method for multiplying numbers is
so easy because it works from left to right

Suppose you want to know the cost of 6 hinges at 73 cents each.

• 73 × 6 = 438
  
  We first multiply the 7 by 6 to get 42.
  
  We then multiply the 3 by 6 to get 18.
  
          4 2 ₁8 = 4 3 8
  
  The 1 in the 18 is mentally carried back to the 42
  to make it 43.
  
  

So any double figure number after the first involves
carrying the first figure to the left and adding it on.

• Similarly 234 × 7 = 1638
  
  We get 2×7=14 then 3×7=21
  and 14 ₂1 = 161
  
  Next we have 4×7=28, so 161 ₂8 = 1638
  
  

• 282 × 4 = 1128
  
  As 8 ₃2 = 112 and 112  8 = 1128
  
  

• And 43 × 7 = 28₂1 = 301 (28 becomes 30)
  
  
  

In The DIY Shop

Mathematics is the
Queen of the Sciences
and Arithmetic the
Queen of Mathematics

GAUSS