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
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.