# An old joke

#### soroban

##### Well-known member

An old Abbott and Costello routine . . .

Lou Costello insists that: $$\;5 \times 14 \:=\:25.$$
Bud Abbott tries to correct him, but Lou "proves" it.

On a blackboard, he writes: .$$\begin{array}{ccc}1&4 \\ \times & 5 \\ \hline \\ \end{array}$$
He says, "Five time four is twenty": . $$\begin{array}{ccc}1&4 \\ \times & 5 \\ \hline \\ 2 & 0 \end{array}$$
Then "Five times one is five": .$$\begin{array}{ccc}1&4 \\ \times &5 \\ \hline \\ 2&0 \\ & 5 \end{array}$$
And before Bud can object, Lou draws the line and adds: /$$\begin{array}{cc}1&4 \\ \times & 5 \\ \hline \\ 2 & 0 \\ & 5 \\ \hline \\ 2 & 5 \end{array}$$
"See?"

Abbott says, "You can't multiply like that! .What if you add five 14's?"

Lou writes:. . $$\begin{array}{ccc}&1&4 \\ &1&4 \\ &1&4 \\ &1&4 \\ + &1&4 \\ \hline \end{array}$$

Bud takes the chalk and adds up the right column: "4, 8, 12, 16, 20 ..."
Lou pushes him aside and adds the down the left column: "21, 22, 23, 24, 25 !"

And has: .$$\begin{array}{ccc}&1&4 \\ &1&4 \\ &1&4 \\ &1&4 \\ &1&4 \\ \hline \\ &2&5 \end{array}$$

Bud says, "You can't add that way either! .Okay, what is 25 divided by 5?"

Lou writes: .$$\begin{array}{cccc}&& - & - \\ 5 & ) & 2 & 5 \end{array}$$
He says, "5 doesn't go into 2, but 5 goes into 5 once": .$$\begin{array}{cccc}&&& 1 \\ && - & - \\ 5 & ) & 2 & 5 \end{array}$$
"One times five is five": .$$\begin{array}{cccc}&&&1 \\ && - & - \\ 5 & ) & 2 & 5 \\ &&&5 \end{array}$$

"25 minus 5 is 20": .$$\begin{array}{cccc}&&&1 \\ && - & - \\ 5 & ) & 2 & 5 \\ &&& 5 \\ &&- & - \\ && 2 & 0 \end{array}$$

"And 5 goes into 20 four times": .$$\begin{array}{ccccc}&&&1 & 4 \\ && - & - & - \\ 5 & ) & 2 & 5 \\ &&& 5 \\ & & - & - \\ & & 2 & 0 \\ && 2 & 0 \\ && - & - \\ \end{array}$$

And Abbott gives up . . .

#### daigo

##### Member

I guess Lou *almost* discovered partial quotient division, but not quite

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