# An estimate helps. An exact check decides. ## Access Show, draw, type, sign, use your usual communication or direct an agreeing helper. Choose quiet/private work, switch a route, pause, pass or finish. One useful part is enough. A helper can read the exact words or scribe your choices; supplying an operation, count, regrouping or reason is mathematical help and is named. No speed, neatness, speech, handling or device requirement. ## Adult model Handouts 268+124=392; 485−392=93 more needed. Budget 265+148=413 cost; 450−413=37 left. Nearest-ten estimate 270+150≈420 checks scale but is not the exact 413 or 37. Keep handouts and dollars separate. ## Child direction Pick a made-up supply or budget job. What decision does the arithmetic need to answer? Pick one route. Show what the numbers mean, try a way, then check one result. You can stop after a useful part. ## Common tangle an estimate is treated as exact; check the roles and equivalent quantities, rather than memorising a printed answer. ## Day 59 ## Different guided practice An imaginary card plan needs 600 cards; 328+195=523 available, gap 77. A separate invented budget $380 costs $197+$186=$383, $3 over. A rough $200+$190≈$390 suggests close but exact arithmetic settles it. ## Check and teach the entry relationship Check sum/difference role and nearest-ten rounding. Show 265 rounds 270 and 148 rounds 150; nearest-ten rough cost 420 differs from exact 413. No cents, retail price or family-finance knowledge assumed. ## Hook Pick a made-up supply or budget job. What decision does the arithmetic need to answer? ## Materials Broad paper, labelled place-value/part-whole/number-line alternatives as suitable; optional familiar safe counters; usual communication. No hundreds of loose marks, purchases or physical handling required. Keep adult model and own work separate. ## Next ordinary teaching If an estimate is treated as exact, compare 49+52≈50+50=100 with exact 101 and target 100. Guide it is 1 over; then invite 98+103 with target 200. Staff reference: 98+103=201, which is 1 over 200. ## Complete fictional source A fictional print stand needs 485 handouts. It has 268 in one pile and 124 in another. Is there enough? Separately a pretend art plan has costs $265 and $148, within an invented AUD450 budget. ## One own invitation Budget $300, fictional costs $148 and $153. Does it fit? Give an exact reason. ## Partial curriculum opportunity 1. AC9M4N08 additive partial 2. AC9M4N07 3. AC9M4N06 ## Purpose Formulate additive practical problems and interpret exact comparisons. ## Routes 1. ### Access Show, draw, type, sign, use your usual communication or direct an agreeing helper. Choose quiet/private work, switch a route, pause, pass or finish. One useful part is enough. A helper can read the exact words or scribe your choices; supplying an operation, count, regrouping or reason is mathematical help and is named. No speed, neatness, speech, handling or device requirement. ### Complete task An invented set needs 90 cards; there are 47 and 36. Find whether more are needed. ### Entry or access Use whole counts rather than a purchase. ### Id A ### Title Small card order ### After own work: adult practice possibility 83 available, 7 more. 2. ### Access Show, draw, type, sign, use your usual communication or direct an agreeing helper. Choose quiet/private work, switch a route, pause, pass or finish. One useful part is enough. A helper can read the exact words or scribe your choices; supplying an operation, count, regrouping or reason is mathematical help and is named. No speed, neatness, speech, handling or device requirement. ### Complete task Use fictional $265+$148 and $450 budget. State total cost and money left. ### Entry or access No real cash handling or spending follows. ### Id B ### Title Art budget ### After own work: adult practice possibility 413 cost, 37 left; about 420 checks scale. 3. ### Access Show, draw, type, sign, use your usual communication or direct an agreeing helper. Choose quiet/private work, switch a route, pause, pass or finish. One useful part is enough. A helper can read the exact words or scribe your choices; supplying an operation, count, regrouping or reason is mathematical help and is named. No speed, neatness, speech, handling or device requirement. ### Complete task An invented print target is 2000 sheets, with 987+1018 available. Estimate then decide exactly. ### Entry or access Compare a rough equality with exact five-extra. ### Id C ### Title Close print decision ### After own work: adult practice possibility 2005 available, 5 surplus; about 1000+1000=2000 is inconclusive. ## Session stages 1. ### Instruction Pick a made-up supply or budget job. What decision does the arithmetic need to answer? Read the source. Ask what the numbers count and the wanted quantity. Check sum/difference role and nearest-ten rounding. Show 265 rounds 270 and 148 rounds 150; nearest-ten rough cost 420 differs from exact 413. No cents, retail price or family-finance knowledge assumed. ### Minutes suggestion 5 ### Stage Meet the job 2. ### Instruction Handouts 268+124=392; 485−392=93 more needed. Budget 265+148=413 cost; 450−413=37 left. Nearest-ten estimate 270+150≈420 checks scale but is not the exact 413 or 37. Keep handouts and dollars separate. Show on separate adult paper. Pause after one transformation; invite explanation before showing the next. ### Minutes suggestion 10 ### Stage Teach one relationship 3. ### Instruction An imaginary card plan needs 600 cards; 328+195=523 available, gap 77. A separate invented budget $380 costs $197+$186=$383, $3 over. A rough $200+$190≈$390 suggests close but exact arithmetic settles it. Offer one complete route below, not all three as a quota. Let the learner select a representation and pause or switch. ### Minutes suggestion 15 ### Stage Guide then choose 4. ### Instruction Budget $300, fictional costs $148 and $153. Does it fit? Give an exact reason. Receive an available response before staff key. If an estimate is treated as exact, compare 49+52≈50+50=100 with exact 101 and target 100. Guide it is 1 over; then invite 98+103 with target 200. Staff reference: 98+103=201, which is 1 over 200. ### Minutes suggestion 5 ### Stage Receive and choose tomorrow ## What to look for A correct additive model, exact 301 and interpretation of $1 over agree; approximate 300 is not affordability proof. ## After own work: staff possibility 301 cost, $1 over. A nearest-ten estimate 150+150≈300 cannot settle the tight decision. ## Status Proposed 35-minute shape, unpiloted and freely reorderable; resource day not school calendar requirement. ## Title An estimate helps. An exact check decides.