How do I react and calm down my child during a tantrum?

Do not respond to aggression with aggression. That’s the first thing to remember. Be calm and hold the child close to yourself. Let her play out the tantrum after which she will naturally calm down. Younger children beat their hands about when throwing a tantrum and tire themselves out physically as well. Then give her something she likes-like a familiar /favorite toy or a drink or something to eat. When she is calm encourage her to talk about the reason for the tantrum and help resolve it.