1. Factors and multiples Review: If you are given a set of numbers… 24 56 …and you need to find the factors, greatest common factor, or lowest common multiples… Start with a factor tree… 24 56 6 x 4 7 x 8 2 x 3 x 2 x 2 7 x 2 x 4 7 x 2 x 2 x 2

2. Factors and multiples 24 56 6 x 4 7 x 8 2 x 3 x 2 x 2 7 x 2 x 4 7 x 2 x 2 x 2 The bottom line is the list of PRIME FACTORS For GREATEST COMMON FACTOR - multiply the numbers that are common to both sets GCF = 2 x 2 x 2 = 8 (there are three 2s in each set) For LOWEST COMMON MULTIPLE - multiply the common multiples by any remaining prime factors LCM = 2 x 2 x 2 x 3 x 7 = 168 - for additional multiples, multiply the LCM by 2, 3, 4…

3. SCIENTIFIC NOTATION REMEMBER… - Multiples of 10 can be expressed in a shorter form with exponents 10 000 = 104 Multiples of numbers other than 1 can also be expressed in a shorter form with powers of 10 and exponents 4 000 000 = 4 x 106 Any number can also be expressed this way by… Putting a decimal after the first digit Rounding off to two decimals after the first digit Expressing the # multiplied by how many powers of 10 would return the decimal to the proper place

4. SCIENTIFIC NOTATION EXAMPLE 1 349 275 Place a decimal after the first digit 1.349275 Round to 2 digits after the decimal 1.35 Multiply by how many powers of 10 it would take to move the decimal back to the end of the original number 1.35 x 106 (multiplying this out would make the number 1 350 000, which is the rounded form of the original #.

5. SCIENTIFIC NOTATION PRACTICE a) 2 479 2.48 x 103 b) 34 951 802 371 3.5 x 1010 c) 467 104 4.67 x 105