- Perfect squares are formed by multiplying a quantity times itself, as in (3)(3) =9 .

Here are six perfect squares: 9, 25, 36, 4

- A 'Difference of Squares' expression is formed by subtracting one perfect square from another one.

Here are four 'Difference of Squares' expressions: 16-9, 49-r

- The Difference of Squares 16-9 can be factored into the two factors (4-3)(4+3).

If you check (4-3)(4+3) , it multiplies together to give you the value 7 which is the same as 16-9.

- The Difference of Squares 49-r

If you check (7-r)(7+r) , it multiplies together to give you the original expression 49+7r-7r-r

[To review multiplying a binomial times a binomial see the other SliderMath games.]

- As a general rule, the Difference of Squares a

You can use the two factors (a-b)(a+b) or you can use (a+b)(a-b). Both answers are equivalent.

- Your Score Report appears after you have made 10 choices.

- Your Game Score is reduced by the number of helicopter hits.

- To slow the game speed repeat tap/click on the word

- To increase the game speed repeat tap/click on the word Math.

- Speed can also be adjusted with a keyboard's - and + keys.

- Refresh/Reload the web page to restart the game.

- Adjust the sound level of media on your device.

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