You might like to make some notes on the course for your own use later. Here is an example of a student's notes.

In order to do arithmetic with mixed numbers like , it is often best to write them as a simple fraction, that is, one number over another.

3.5 Several calculations and using brackets

Sometimes you may want to make several calculations in succession, and the order in which the calculations are performed may or may not be significant. For example, if you want to add 12 + 7 + 13, it makes no difference which of these two processes you adopt:

add the 12 and 7 first, to give 19, and then the 13, to give 32;

or

add the 7 and 13 first, to give 20, and then add this to 12 to give 32 again.

1.8 Simplest form of a fraction

The fraction , is the *simplest form* of all its equivalent fractions, because it cannot be ‘simplified’ further (by dividing top and bottom by the same whole number called a **common factor<**

**Activity 18**

**Write down the coordinates of the points A, B, C, D and E.**

**Author(s):**

**To subtract one number from another without using a calculator you need to know basic subtractions up to 20. This means that you need to know, off by heart, what result you get if you subtract any number up to 10 from any bigger number up to 20. For example you have to remember that 14 minus 6 is 8, or 9 minus 5 is 4, and so on. **

**If you are confident that you know the basic subtractions up to 20, carry on with the rest of this course. If you are unsure, or would like some practice to he**

**3.3 HIV testing in sub-Saharan Africa **

**Example 3.2 HIV testing in sub-Saharan Africa**

**In developed countries, the standard method for testing whether a person is infected with the virus HIV, that causes AIDS, is to carry out a blood test. Provided such a test is carried out long enough after the initial infection occu**

**Activity 1 Drawing a boxplot: chondrite meteors**

**For many purposes the location and dispersion of a set of data are the main features of its distribution that we might wish to summarise, numerically or otherwise. But for some purposes it can be important to consider a slightly more subtle aspect: the symmetry, or lack of symmetry, in the data.**

** Example 4: Fami**

**5.6.2 Quartiles when the sample size is awkward **

**For the six ordered data items 1, 3, 3, 6, 7, 7, the lower quartile is given by**

**In other words, the lower quartile q_{L} is given by the number three-quarters of the way between x _{(1)}=1 and x _{(2)}=**

**3.1 Have I done the right calculation? **

**Once you have done a calculation, with or without the aid of a calculator, it is important that you pause for a moment to check your calculation.**

**You need to ask yourself some questions.**

**Have I done the right calculation in the right order?****Have I given due consideration to units of measurement?****Is my answer reasonable?****Did I make a rough estimate to act as a check?**

**Your calculation wil**

**Activity 14**

** Measurement of a ceiling gives a length of 6.28 m and a width of 3.91 m.**

**(a)**Make a rough estimate of the area of the ceiling (the length times the width).

**1.2.1 Rounding to the nearest hundred **

**You will probably think to yourself that the coat shown costs about £300. £290 is considerably closer to £300 than it is to £200, so £300 is a reasonable approximation. In this case, 290 has been rounded up to 300. Similarly, 208 would be rounded down to 200 because it is closer to 200 than it is to 300. Both numbers have been rounded to the nearest hundred pounds.**

**When rounding to the nearest hundred, anything below fifty rounds down. So 248 rounds to 200. Anything o**

**We shall use the symbol (known as tilde or twiddle) to represent a relation between two elements of a set.**

**Some texts use ρ, rather than Author(s): **

**In this final section we look at a method of classifying the elements of a set by sorting them into subsets. We shall require that the set is sorted into disjoint subsets – so each element of the set belongs to exactly one subset. Such a classification is known as a partition of a set. In order to achieve a partition, we need to have a method which enables us to decide whether or not one element belongs to the same subset as another. We look first at the general idea of a r**

*Exercise 51*

*Exercise 51*

*Evaluate the following sums and products in modular arithmetic.*

*(a) 21 +*_{26}15, 21 ×_{26}15.*(b) 19 +*_{33}14,

*Task 10 The Möbius band*

*Task 10 The Möbius band*

*Take a long thin strip of paper (preferably squared or graph paper) about 30 cm by 3 cm. Give one end a half twist and then tape it together. This is a Möbius band as shown in Author(s): *

*Capacities for managing development The way forests around the world are managed is undergoing radical change. In the UK, local communities are buying forested land, to preserve forests for the greater benefit of society. In the developing world, forestry commissions are actively empowering villagers to engage in forest management and conservation. The video tracks on this album use case studies in the UK and in India to illustrate ways in which forest management is changing, and how such changes can be implemented. To complete th*

*
Pages
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477
Copyright 2009 University of Nottingham
*