A greater share of back-to-school spending is expected to go toward electronics, as parents outfit kids with tablets, e-readers, cellphones and wearable gadgets and sign them up for e-learning program subscriptions to keep them from falling behind after last year's disruptions. Families are on track to spend $37.1 billion on back-to-school, up 9.4% from last year, according to a National Retail Federation survey.