Decimals and Fractions

Fractional / Decimal blocks

We had some fun making fraction/decimal blocks for use when completing the square and squaring decimal numbers ending in five. Below is the zero pair used when completing the square of the quadratic polynomial x² – 7x + 10 using blocks. It is the same zero pair used when completing the square on paper.

x² – 7x + 10
(x² – 7x) + 10
(x² – 7x + 12.25) – 12.25 + 10
(x² – 3.5)² – 2.25

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Crewton Ramone’s House of Math pointed out if we change the scale of the blocks we can also square integer numbers ending in 5.

– the possibilities are endless.

Here is a DIY video showing how to cut up the MM blocks.


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