Estimate the yield from each of the crops you have grown, then measure the produce from one plant and ask pupils to refine their estimate of the total yield, either in weight or by number. If the crop is to be shared equally between every class in the school, what quantity might each class expect to receive? What other ways can this be expressed? You could, for example, use decimals and fractions. You may decide to sell the produce. Research market prices, calculate packing costs and estimate the income. Keep a record of the yield from each plant (they may be harvested at different times). Use this to work out average yields per plant.
Rectangular arrays Key stage 1
The class has grown 20 cabbages or leeks in pots, from seed. They are now big enough to plant out and there is a choice of rectangular beds for them. Ask pupils to arrange the plants in as many rectangular arrays as they can. Some seeds did not germinate, so explore whether all those that did would make a rectangular array.
Key stage 2
Plant a bed of cabbages in a 3 x 8 rectangular array. Ask pupils to suggest two multiplications that describe the array and explore the corresponding division calculations. Discuss how the cabbages could have been planted in a different rectangular array. Pupils can use 24 seeds (large enough to be handled) and position them on squared paper.
Planning next year's harvest
Count the number of seeds in a packet (select seeds large enough to be handled). If they all germinate, how many plants will you have? How much space will be needed to grow them all? If each plant needs 30 centimetres of space, how many seeds can be planted in a specified bed? Survey the class to discover their three favourite vegetables. Pupils should collect this data and present their results in different ways, such as ratios and proportions. From this data, ask the children to suggest a planting scheme for an area in their school grounds. They should measure the area and draw on squared paper. Estimate the size of the harvest for each vegetable, with pupils determining the number of plants needed of each vegetable, so the harvest is in proportion to class preferences.