Dividing fractions: 2/5 ÷ 7/3 (Khan Academy)

[One speaker] 

[Video opens to a black screen with the equation “2/5 ÷ 7/3.” The narrator uses the cursor to write on the screen throughout the video.]

Narrator: So let’s calculate what two fifths divided by seven thirds is, and I encourage you to pause this video and try to calculate this on your own. Well, we just have to remind ourselves that this is going to be the exact same thing as two over five times the reciprocal of seven thirds, which is three over seven [writes “2/5 × 3/7=”]. And then multiplying two fractions is pretty straightforward. This is just going to be equal to the product of the numerators. So two times three over the product of the denominators, over five times seven… I’m trying to keep the colors consistent… which of course is going to be equal to two times three [writes “(2×3)/(5×7)=], is equal to six. And five times seven, I’ll do this in a new color, let’s see… I haven’t used this shade of blue yet… five times seven of course is equal to thirty five. So this is equal to six over thirty fave [writes “6/35”].

[End of Video]