Question

30*5=

Answer 1

150

Answer 2

thanks

Answer 3

your welcome you couldve used a calculator though

Answer 4

30
*5 take 5 and multiply it by 0 then multiply it by 3
------
150

Answer 5

@warood If you have them start using calculators before they need them for graphing, they'll never learn how to do basic stuff on their own.

Answer 6

ya thats true

Answer 7

Well a nice way to represent it is:
\[30\times5=(3\times10)\times5\]
We know that:
\[(a\times b)\times c=a\times(b\times c)\]
So we can simplify:
\[\eqalign{
&(3\times10)\times5 \\
=&(3\times5)\times10 \\
=&(3+3+3+3+3)\times10 \\
=&(6+6+3)\times10 \\
=&(12+3)\times10 \\
=&(15)\times10
}\]
When you multiply anything by 10, you add a digit of zero on the end so:
\[15\times10=15{0}\]