IB Math Studies Mrs. Drehmer 2.1 Organization of Numbers 5 , and -5. Complete the table below, showing , these numbers belong to. 1. Consider the numbers 5, 0.5, which of the number sets, 2. Given Z the set of integers, Q the set of rational numbers, and R the set of real numbers: a) Write down an element that belongs to R ∩ Z. b) Write down an element that belongs to Q ∩ Z’. c) Write down an element that belongs to Q’. d) Use a Venn diagram to represent the sets Z, Q and R. IB Math Studies Mrs. Drehmer Indices/Exponents \ IB Math Studies Mrs. Drehmer Prime Numbers/Factors/Multiples IB Math Studies Mrs. Drehmer 2.2 Numbers in Calculations http://www.sciencegeek.net/Chemistry/taters/Unit0SigFigCounting.htm 1. 2. How many significant figures does each number have? To what place value has the number been rounded? a) 43.5 b) 5673.7 c) 1200 d) 4.001 e) 0.00452 f) 0.00340 g) 784000 h) 0.450 i) 4503450 Round the following values to the requested number of significant figures or place value: a) 2.526 [2 sf] e) 0.4523 [2 sf] b) 2.526 [hundredths] f) 3.684 [tenths] c) 24650 [1 sf] g) 5.6720 [hundredths] d) 45627 [3 sf] h) 0.04537 [3 sf] IB Math Studies Mrs. Drehmer 2.2 Numbers in Calculations When we round our answers, we are changing an exact answer into an approximate error. This introduces error into our calculation. IB expects you to find how much error there is. To find percent error, find the difference between the exact answer and the approximate answer, and then divide by the exact answer. Multiply by 100 to change to percent. 𝑃𝑒𝑟𝑐𝑒𝑛𝑡 𝑒𝑟𝑟𝑜𝑟 = 3. 4. 𝑣𝐴 − 𝑣𝐸 × 100 𝑣𝐸 Given the equation p r 2 2qr , a) Calculate the exact value of p then q = 3.6 and r = 24. b) Write your answer correct to two significant figures. c) Find the percentage error between a) and b). For each figure below: a) b) c) Use your formula booklet to find the exact area. Round your answer to the nearest tenth. Calculate the percentage error between your two answers. IB Math Studies Mrs. Drehmer 2.3 Standard Form 1. A box contains 1.81 x 1024 atoms. One third of them are carbon, the other two thirds are oxygen. How many carbon atoms are in the box? How many oxygen atoms? 2. a) Given x = 2.6 × 104 and y = 5.0 × 10−8, calculate the value of w = x × y. Give your answer in the form 𝑎 × 10𝑘 where 1 ≤ 𝑎 < 10 and 𝑘 ∈ ℤ. b) Which two of the following statements about the nature of x, y, and w are incorrect. 3. 4. The total weight of 256 identical pencils is 4.24 kg. Calculate the weight of one pencil, in kg. a) Give your answer exactly. b) Give your answer correct to three significant figures. c) Write your answer to part b) in the form a 10 k where 1 a 10 and k . Let x 6.4 107 and y 1.6 108 . Find a) x y b) y 2x giving your answers in the form a 10 k where 1 a 10 and k . IB Math Studies Mrs. Drehmer 2.4 International Units of Measure 1. A field is 91.4 m long and 68.5 m wide. a) Calculate the area of the field in m2. b) Calculate the area of the field in cm2. c) Express your answer to b) in the form 𝑎 × 10𝑘 , where 1 ≤ 𝑎 < 10 𝑎𝑛𝑑 𝑘 ∈ ℤ. 2. 3. The speed of sound in air is given as 300 m s-1. a) How many metres does sound travel in air in one hour? b) Express your answer to part a) correct to two significant figures. a) Convert 0.001673 litres to millilitres (ml). Give your answer to the nearest ml. The SI unit for energy is Joules. An object with mass m travelling at speed v has energy given by b) 1 mv 2 (Joules). 2 Calculate the energy of a comet of mass 351223 kg travelling at speed 176.334 m/sec. Give your answer correct to six significant figures. In the SI system of units, distance is measured in metres (m), mass in kilograms (kg), and time in seconds (s). The momentum of an object is given by the mass of the object multiplied by its speed. c) Write down the correct combination of SI units (using m, kg, s) for momentum.