L2 · The missing start: • − f = g

Learning goal

“I can find the missing start in a subtraction sentence.”

Start — the whole number we begin with, before anything is taken away.

Take away — the part that is removed in a subtraction.

Left — the part that stays after the take away.

Worked example

Find • in • − 3 = 5. The start is the whole. It was split into the part taken away (3) and the part left (5). Add the parts back: 5 + 3 = 8. The start is 8. Check: 8 − 3 = 5 - taking 3 from 8 leaves 5, just like the sentence says.

Check yourself — explain it

How does adding help us here?

Paired problem — example still visible

Find • in • − 2 = 6 -> 8 (add back: 6 + 2 = 8; check: 8 − 2 = 6)

Faded completion — last step is yours

"• − 4 = 3. Add the parts back: 3 + 4 = ___. That number is the start." -> 7

Ready to practise?

8 scored questions with a 3-rung hint ladder. Mastery needs 7/8 plus both gate questions.

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