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Grade 4 · Maths · Lessons
Two steps, then check it
1️⃣step 12️⃣step 2🔍check🔢round
Two steps.
The big ideaDo one step, then the next. Read what the leftover means. Check it by rounding.

How it works

Do one step, then the next. Read what the leftover means.

Check by rounding: does the answer make sense?

Use a letter for the unknown if it helps.

Find the first totalUse it in step twoCheck by rounding
Two steps.

Example 1: Multiply, then add

  1. Ravi has 4 bags with 12 marbles in each. He gets 35 more. How many marbles does Ravi have now?
  2. 4 bags of 12 is 4 × 12 = 48.
  3. 48 + 35 = 83.
  4. So the answer is 83.

Example 2: A bigger one

  1. Nora has 5 packs with 25 stickers in each. She gets 92 more. How many stickers does Nora have now?
  2. 5 packs of 25 is 5 × 25 = 125.
  3. 125 + 92 = 217.
  4. So the answer is 217.

Example 3: Check by rounding

  1. Kofi has 4 bags with 489 beads in each. He gets 1,163 more. How many beads does Kofi have now?
  2. 4 × 489 is about 4 × 500 = 2000.
  3. 4 × 489 = 1956, and 1956 + 1163 = 3119.
  4. So the answer is 3119.

Words to know

step
One part of a problem.
estimate
A close answer made by rounding.

Watch out

Try it

  1. Kofi has 2,030 beads. He gives away 1,004. He shares the rest equally between 2 friends. How many beads does each friend get?
  2. Kofi has 6 bags with 890 beads in each. He gets 655 more. Which sentence tells the story?
  3. Kofi shares 6,692 beads equally between 7 friends. Then each friend gives away 140. Which sentence tells the story?
Answers: 1. 513 · 2. 6 × 890 + 655 = n · 3. 6,692 ÷ 7 − 140 = n
For grown-upsEstimate before solving: 'is it about 80 or about 800?'
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