Estimate sums, differences, products and quotients: word problems

Key notes :

1. Estimation:
   • Estimation is a way to find a rough answer that is close to the exact answer.
   • It helps to quickly assess whether an answer makes sense.
2. Rounding Numbers:
   • Round numbers to the nearest ten or hundred to simplify calculations.
   • Example:
     • For 67, round to 70.
     • For 134, round to 100.
3. Operations:
   • Understand the four basic operations:
     • Addition (sum)
     • Subtraction (difference)
     • Multiplication (product)
     • Division (quotient)

Estimating Sums and Differences

• Sums:
  • Round each number to the nearest ten and then add.
  • Example: Estimate 48 + 37 :
    • Round 48 to 50 and 37 to 40.
    • Estimated sum = 50 + 40 = 90.
• Differences:
  • Round the numbers to the nearest ten and then subtract.
  • Example: Estimate 92 − 25:
    • Round 92 to 90 and 25 to 30.
    • Estimated difference = 90 − 30 = 60.

Estimating Products and Quotients

• Products:
  • Round each number to the nearest ten or hundred before multiplying.
  • Example: Estimate 23 × 15 :
    • Round 23 to 20 and 15 to 20.
    • Estimated product = 20 × 20 = 40.
• Quotients:
  • Round the dividend and divisor to the nearest ten before dividing.
  • Example: Estimate 64 ÷ 8:
    • Round 64 to 60 and 8 to 10.
    • Estimated quotient = 60 ÷10=6.

Learn with an example

Let’s practice!🖊️