One of the trickiest questions our collaborators face when doing the Brightworks arc is knowing when explicit skill building needs to happen to help the kids’ explorations make more sense and become more meaningful.

Last week, Mackenzie’s band faced such a conundrum when they tried to measure the distance from Brightworks to the park using multiplication for estimation:

Mackenzie writes, “The most interesting problem of the week was inspired by the meridional definition: the meter is 1 ten millionth of the distance from the equator to the north pole. I gave our group a similar challenge to the one faced by the mathematicians who had to figure out the actual distance from the north pole to the equator.


I asked our group to figure out the distance from BWX to the park without leaving our city block. There were two main approaches to this problem. Half of the group walked heel to toe from one corner of the block to the other keeping count all the way, while the others measured a single paving square then counted how many paving squares in a block. Gathering the information from the city block had several challenges; however, the part that was most difficult for the group was the long addition and multiplication needed to estimate the distance beyond our city block. We had come to an impasse because the group didn’t have enough practice in the tools they needed to solve this problem.

This led me to grapple with one of the questions we face as we develop a BWX math program: How do we provide for the repetition and explicit instruction needed in building math skills while keeping in the spirit of exploration?


This week I decided that our group would take a detour into some explicit skill building with base-10 blocks. We spent three days this week using ‘base 10 blocks’ to build their understanding of place value in long addition and create arrays to help symbolize multiplication problems.”


This week, they are picking the exploration part of the problem back up and collaborating with Lili’s band to make estimations from here to the park and here to Dolores Park.