In this week’s parsha, we learn about manna, the miraculous food that Hashem sent to feed the Jewish people in the desert. As an extra miracle, Hashem sent a double portion on Friday so the Jews would not need to collect manna on Shabbat. And that manna did not rot like the manna would on other days.

Many Jews wonder what the desert experience was like and wish they could see all of the miracles and receive the Torah at Mount Sinai in person. Well, when we eat from two Shabbat challahs, we get a taste of it—quite literally. And the more impressive part is that we can use math to go back to the desert experience! Here’s how:

We can calculate the volume of our challahs and convert the number into portions of manna. We learn in the Torah that the manna’s volume was an omer and that was a tenth of an ephah (Shemot 16:36). Many rabbis today estimate that an ephah was about 25,000 cubic centimeters. Say a family uses two large challahs for Friday night that each measure 40 cm x 20 cm x 25 cm. How many omers would that be?

Solution:

An omer is about 2,500 cm cubed since we learned in the Torah that 10 omer = 1 ephah and 25,000/10 = 2,500. The volume of the two challahs is 40,000 cm cubed since we have the chain of calculations 40 x 20 = 800, 800 x 25 = 20,000, 20,000 x 2 = 40,000. When we divide the volume of the challahs by the volume of an omer we get 16 omers. (40,000 / 2,500 = 16).

I hope you enjoy your challahs this Shabbat and can think of the manna at the same time. Shabbat Shalom.

Ari Blinder is a math educator living in Highland Park, New Jersey, and the owner of Math for the Masses, an innovative math tutoring and consulting company. For more information, visit https://www.math4masses.com. Ari can be reached at [email protected].