We first became acquainted with Mrs. Daftari's fifth-grade class earlier this year when they rose to a challenge printed in PopSci by submitting their essays for how they'd change the world. Most recently, they sent us these video responses to our 5-Minutes Projects series. In the second, McKenna Mooney and Madison Wilson replicate Megan Miller's DIY non-Newtonian fluid (otherwise known as slime). And in the first, Kacie Moore and Olivia Johnson present a project of their own: the sound catcher.