I have an interview coming up requiring my to teach 30 mins maths to a full class of mixed ability year 1/2's. Have been informed I will not be given information on attainment groupings within the class. I know what I want to do for the lesson but have now got myself in a complete tiz about how to organise and differentiate when I won't know the kids. I have chosen a number objective and have in mind 3 way differentiated activities, but how will I know how to group the kids for this? I know I should assess in a short starter, but don't think I could get enough from this to accurately group all the kids to the 3 activities. Going round in circles! Any advice appreciated.