Teaching article
A missing addend is a quantity to find
Make the unknown part visible as a space to be filled, not a cue to guess.
Cover one part of a visible addition model while leaving the total and other part known. The empty space now represents a specific quantity, rather than a cue to perform whichever operation looks familiar.
To hand: A target of ten and six counters.
Build the known part. Add counters until reaching the target. Record the missing quantity.
Identify the role of the blank
Six plus an unknown amount equals ten; four additional counters complete the collection.
Identify which quantity is unknown and how it relates to the known quantities. A blank need not always appear after the equals sign.
How does the completed model verify the answer? Use a ten-frame with empty spaces.
The target total and the missing part are different quantities.
Resources
- Maths Puzzle Generator — Choose arithmetic or missing-number questions only when they match the number relationship being explored.
Further reading
Read next
- Equal groups give multiplication a structure
- Two pieces are not automatically two halves
- One object, one count: make the correspondence visible
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