Today’s problem — free all day, every step. Every day has one.
Flags for a parade — reels of string
A scout troop is preparing 320 flags for a parade. Each flag needs 45 cm of string to tie it to a pole. String is sold in reels of 10 m. How many reels must the troop buy?
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MathBrush is being tested with a few parent groups, and every solution on the site is open to them — one household, all children. If you were given a code, it goes in once and this device remembers it.
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65 worked examples are free without a code, two from every pattern. No account, either way.
The pattern behind it: Number × value
One batch repeats. Work out one batch, then multiply.
In this one. Round down when counting complete lengths from one reel, then round up when counting whole reels to buy.
How to spot it
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.
Common mistake
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.
Try one like it
Standard Ribbon length Jess needs 200 ribbons, each 110 cm long. Ribbon is sold in tapes of 25 m (2500 cm). How many tapes does she need?The 33 problem patterns
All 33 patterns, one to a page — the 19 behind Primary 5 and 6 word problems, and the skills the younger years are built on. The bar model, how to spot it in the question, and the mistake children make. A booklet you can print. Free.
A PDF, and a note when new solutions go up.