Prealgebra for Two-Year Colleges/Appendix (procedures)/Multiplication table


 * 1) What pattern do you notice if you fold the table across the diagonal?


 * The numbers are the same on either side of the diagonal; the table is symmetrical.


 * 1) Explain this pattern mathematically.


 * We get the same answer when we change the order of the factors. For example, 8*5 = 5*8. This is called the commutative rule of multiplication.


 * 1) Write this rule in symbolic notation.


 * x*y = y*x


 * 1) What happens when you go across the 4’s row?


 * We are counting up by fours. We add four each time.


 * 1) What happens when you go down the 7’s column?


 * We are counting up by sevens. We add seven each time.


 * 1) Anything times 1 is...


 * ...the same thing.


 * 1) Write this rule in symbolic notation.


 * x*1 = x


 * 1) Anything times 0 is...


 * ...zero.


 * 1) Write this rule in symbolic notation.


 * x*0 = 0