Problem
1 lb is 16 oz, so it holds 16 / 8 = 2 portions of 8 oz. At $4 each, the tomatoes cost 2 × $4 = $8.
Converting 1 lb to 16 oz so the weight matches the 8 oz unit of the price is just unit sense a third grader builds with measurement.
3.MD.A.2Analyze The UnitsOne pound of cherry tomatoes, priced at 8.
One pound of tomatoes is the same weight as two 8-ounce portions, and each 8-ounce portion is priced at 4.
One pound splits into exactly two 8-ounce portions, since one pound is sixteen ounces.
Sixteen ounces holds exactly two 8-ounce portions because two equal groups of 8 make 16.
Those two 8-ounce portions together are the entire pound, with no weight left over or counted twice.
Two portions that each cost 8, since two equal groups of 4 added to itself.
1 lb 8 oz is 1 lb plus half a pound. At $9 per pound that's $9 + half of $9 = $9 + $4.50 = $13.50.
Recognizing 8 oz as half a pound and taking half of the per-pound price is a within-100 multiplication/division word-problem skill.
3.OA.A.3Identify SubproblemsAdd the tomato cost and the pork cost: $8 + $13.50 = $21.50.
Combining the two subtotals is a single addition of two money amounts.
3.OA.A.3Identify SubproblemsMatch the weight to the price's unit, find each cost, then add - that's just Grade 3 unit sense!