 Bournemouth Maths Tutor Barney M-T Strange but True: IRRATIONAL NUMBERS

The first numbers we discover in childhood are the Natural Numbers: 1, 2, 3, … Next come the Integers (whole numbers) – which also include Zero and the negatives: … -3, -2, -1, 0, 1, 2, 3, … Next up: it’s fractions such as: 0.5, 2.90909… , $-\Large{5}\frac{7}{8}$ Numbers like these are said to be (or: Much ado about Nothing) Zero doesn’t actually exist. Think about it: by definition it isn’t anything, it’s nothing!! Even so, here are 5 facts every mathematician should know about Zero: WORD OF THE WEEK: INDEX

INDEX (plural indices): you can see these in expressions like $5^2 = 25$. The 5 is called the BASE, the 2 is called the EXPONENT or INDEX, and the 25 is called a power (in this case it’s a power of 5). WORD OF THE WEEK: TRIGONOMETRY

TRIGONOMETRY is the branch of maths to do with sin, cos and tan (find them on your calculator). Literally it means “measuring triangles” – so you can use these three functions to find unknown lengths and angles. Sin is short for “sine” – which is why it should be pronounced “sign” not “sinn”. Cos and