Question P6 Number × value
Today’s problem — free all day, every step. Every day has one.
The figure shows a rectangular display case and an L-shaped countertop border around it in a bakery. The width of the border is 40 cm. The border is covered with 30 circular coasters of diameter 20 cm, following the pattern shown in the figure. Each coaster touches the ones next to it. What is the area of the border not covered by the coasters? (Take π = 3.14)
Answer
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One batch repeats. Work out one batch, then multiply.
In this one. Pair every coaster with its own 20 cm by 20 cm square slot, find the same uncovered corner area once, then multiply that value by 30.
Items are described as a fixed group or ratio that repeats, such as tiles following a pattern, snacks sold in a fixed mix, or a rate given per hour or per item.
Children start from the grand total instead of first working out what one batch is worth. In rate questions they also confuse a duration with a clock time.
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