Summer Opportunities & How to Multiply 9 Digit Numbers in Your Head

Like MC2, a number of summer programs have now committed to running their camps online:

1. MC2’s Camps

Our lottery runs on Friday, 5/15. Camps will run the weeks of 7/13 and 7/20, serving rising 6th to 13th graders.

2. The Stanford Summer STEM Institute

This camp runs from June 21st to August 1st. It consists of a research and data science bootcamp, a masterclass lecture series, and  a guided research project. Rising 9th to 12th graders. Admission is on a rolling basis, so apply ASAP.

3. Wolfram High School Summer Camp

Wolfram has reached out to MC2, and they are looking to recruit more female students. The camp runs from July 5th to July 18th, and participating students will get an opportunity to learn the Wolfram programming language, engage in special computing topics like natural language and machine learning, while also having individual project time.

4. MyChiMyFuture

Mayor Lightfoot will be launching the MyChiMyFuture website on May 11th. You’ll find links to summer programs offered by Chicago out-of-school providers. This site will be a clearinghouse for the summer and beyond, from camps to online challenges to meet-ups!


Now, how do you multiply 9 digit numbers in your head?

First, and yes, this is a trick, one of the numbers has to be 142,857,143. But the other one can be anything you’d like! Here’s an example:

142,857,143 x 358,246,974

Steps below will be written out, but with practice you can do them all in your head.

Step 1: Write the chosen number twice: 358,246,974,358,246,974

Step 2: Take the number from step 1 and divide it by 7, moving left to right. That’s it! In this case:

35/7 = 5

8/7 = 1 with remainder 1, which you connect to the 2, the next digit
12/7 = 1, remainder 5, which you connect to 4, the next digit

54/7 =7, remainder 5

56/7 = 8

9/7 = 1, remainder 2, etc.


So, 142,857,143 x 358,246,974 =


Works every time!