Presentation on theme: "“We cannot hold a torch to light another’s path without brightening our own.” – Ben Sweetland Check homework Odds w/book Evens with a neighbor Sections."— Presentation transcript:
“We cannot hold a torch to light another’s path without brightening our own.” – Ben Sweetland Check homework Odds w/book Evens with a neighbor Sections 2.1 – 2.4 No more than 5 minutes! Warm-up
2.5 Multiplication of Integers Properties of Multiplication a * b = b * a The order of 2 numbers being multiplied does not matter. 1 * a = a The product of one & a number is that number. 0 * a = 0 The product of zero & a number is zero.
-1 * a = -a The product of a number and -1 is the opposite of that number. a * -b = -ab The product of a and –b is the opposite of ab. Multiplying 2 numbers with different signs is ALWAYS a negative answer. -a * - b = ab The product of –a and –b is ab. Multiplying 2 numbers with the same sign is ALWAYS a positive answer.
Sect. 7 – Division of Real # The integer rules for division are the same as for multiplication. Same signs = positive answer -20/-4 = 5 Different signs = negative answer -20/4 = -5
Division can be written as multiplication. Reciprocals – numbers when multiplied together equal 1 (excluding 1 * 1) –Reciprocal of a/b is b/a –Reciprocal of 4 is ¼ Division w/reciprocals –To divide “a” by “b”, you can multiply by the reciprocal of “b” and get the same answer. –20/4 is the same as 20 * 1/4
Write the division as multiplication & solve 3/5 divided by 2 = 3/5 * ½ = 3/10 3x divided by 1/3 = 3x * 3 = 9x -x / (-6) = -x * (-1/6) = x/6