During the COVID-19 pandemic, many parents suddenly had to assume responsibility for their children's learning at home. Research conducted before the pandemic showed that mathematics homework is often unsuccessful or stressful for both parents and children and that tension exists between home and school in the learning of mathematics. Understanding parents' experience of home-learning mathematics during lockdown has implications for positive learning relationships between home and school in the future. During the lockdown, we sent an online survey to New Zealand parents and received 634 responses. We found that parents were generally very engaged in the home learning of mathematics. They reported a range of opinions about the quality of mathematics work and teacher support, and there was a correlation between general stress levels and negative opinions. To further support their child's mathematics learning, many parents turned to online mathematics programs, about which they were very positive. Parents of younger children were more positive about their overall home-learning experiences of mathematics, but the crisis brought to the fore several pre-existing issues. We argue that these findings have implications for mathematics home learning in the future; we suggest that schools listen to parental feedback regarding the quality, level, and quantity of mathematics work. Additionally, schools could consider ways to deliver effective teacher support and to foster parental agency in helping their children with mathematics learning.