Grade 5 › G5U01 Place Value

Grade 5 › G5U01 Place Value › L4
GRADE 5 · ALBERTAOUTCOME AB-G5-5N1

L4 · Rounding to various places, according to context

Learning goal

“I can round whole numbers and decimals to any place - millions down to thousandths - using the midpoint rule, and I can choose the place that fits the context of a problem.”

Round — to replace a number with a nearby number that has zeros (or fewer decimal places) after a chosen place, e.g. rounding 4,582,913 to 4,600,000.
Nearest — closest in value: 26,499 is nearer to 26,000 than to 27,000.
Halfway point — the number exactly in the middle of two rounding neighbours; 26,500 is halfway between 26,000 and 27,000. Numbers at or above the halfway point round up.
Context — the situation around a number, which tells you what precision matters: a flyer price needs the nearest dollar; a ribbon length may need the nearest hundredth.
Worked example

Round 4,582,913 to the nearest hundred thousand. Step 1 (neighbours): the hundred-thousands neighbours are 4,500,000 and 4,600,000. Step 2 (halfway): the halfway point is 4,550,000. Step 3 (decide): 4,582,913 > 4,550,000, so it rounds UP to 4,600,000. The digit shortcut says the same thing: look at the digit after the rounding place (8, in the ten-thousands place) - 5 or more means round up. The rule is identical for decimals: round 7.385 to the nearest hundredth - neighbours 7.38 and 7.39, halfway 7.385; the number sits exactly ON the halfway point, and by convention halfway rounds up: 7.39.

Check yourself — explain it

A number exactly at the halfway point rounds up because...

Paired problem — example still visible

Round 0.472 to the nearest tenth -> 0.5 (neighbours 0.4 and 0.5; halfway 0.45; 0.472 > 0.45)

Faded completion — last step is yours

"385.294 to the nearest hundredth: neighbours 385.29 and 385.30; the next digit after the hundredths place is 4, so it rounds ___ to ___" -> down; 385.29

Ready to practise?

10 scored questions with a 3-rung hint ladder. Mastery needs 8/10 plus both gate questions.

Start practice →Take the unit quiz