Sticker collection — four friends
Four friends collected stickers over the summer. Ana collected 8 fewer stickers than Ben. Cara collected twice as many stickers as Ben. Dee collected 4 fewer stickers than Cara. Together the four friends collected 90 stickers. How many stickers did Dee collect?
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The pattern behind it: Units and parts
Cut one amount into equal shares. One number tells you what a share is worth.
In this one. Complete each shortened bar: adding the missing 8 and 4 to the total turns 90 stickers into 6 equal Ben units.
How to spot it
A single amount is split by a ratio, a fraction or a percentage. One extra number gives you the leftover, the difference, or the value of one share.
Common mistake
Children match the given number to the wrong number of shares, using the whole bar when the number covers only the leftover or the difference between two people's shares.
Try one like it
Standard Class trip savings — four classmates Four classmates saved money for a class trip. Liam saved $15 less than Sara. Priya saved twice as much as Sara. Tom saved $9 less …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.
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