Author note — to cover

Subtractions like 4.03 - 1.276 and 3000 - 847 where the exchange must travel through one or more zeros, showing where each borrowed unit comes from and the reindexed digits. Assumes column-subtraction; do not reteach basic single-column exchange here. Both tiers. (N2)

• Integers — subtract values such as 3000 − 847 where an exchange passes through one or more zeros (4 questions).
• Decimals — subtract values such as 4.03 − 1.276 with zero place-holders and chained exchange (4 questions).
• Application — solve subtraction contexts whose written method requires an exchange across zeros (4 questions).