Babylonian Maths Numbers in base 60 • What do you think these five numbers are? • What do you think these five numbers are? 20 • What do you think these five numbers are? 20 40 • What do you think these five numbers are? 20 40 53 • What do you think these five numbers are? 20 40 28 53 • What do you think these five numbers are? 20 40 28 53 49 In base 60 … • Any number between 1 and 60 corresponds to the units in our numbers. • Getting to 60 in base 60 is like getting to 10 in base 10. • We don’t need a new symbol when we get to 10, and the Babylonians didn’t need a new symbol for 60. • What do you think these three numbers are? 60 + 1060 + 20 120 + 10 = 70 = 80 = 130 • What do you think these two numbers are? 2 x 60 + 13 = 133 3 x 60 + 28 = 208 Writing numbers in base 60 • You don’t have to write base 60 numbers in cuneiform symbols. • Look at these base 60 numbers – can you work out what they mean? Base 60 0 18 Base 10 18 1 39 60 + 39 = 99 3 06 11 20 180 + 6 = 186 660 + 20 = 680 • Can you change these base 10 numbers into base 60? Base 10 29 69 149 299 Base 60 29 1 09 2 29 4 59 Zero • The Babylonians didn’t have a separate symbol for 0. • This number would have meant 3600 + 1 = 3601 • The zero lots of 60 would have just been a gap. • Is this a good way of showing a zero, do you think?