To do this we're using the equals sign = and the plus sign +. As here, in 'Make a Face':
This week we used this interactive page - https://nrich.maths.org/2724 - to talk about which red/white trains can be made to have the same length as the yellow rod. (You might like to have a go at home!) We also talked about how to write down what we'd found.
Of course, we had a go at this with the real rods, and had a go at writing down what we'd made.