What Does It Mean to Estimate Sums?
Estimating sums means making a good guess about what numbers add up to, without calculating the exact answer.
It's like when you look at your piggy bank and guess about how much money you have, without counting every single coin. We use rounding to make numbers easier to work with in our heads!
How to Estimate Sums
1️⃣ Round each number to the nearest ten or hundred
2️⃣ Add the rounded numbers together
3️⃣ Check if your estimate makes sense - is it close to the real answer?
Let's Practice Estimating!
Example 1: Shopping Trip
You want to buy a toy for $47 and a book for $32. About how much money will you need?
Let's estimate:
Round $47 to $50 (because 47 is closer to 50 than to 40)
Round $32 to $30 (because 32 is closer to 30 than to 40)
Now add: 50 + 30 = about $80
The exact answer is 47 + 32 = 79. Our estimate of 80 was very close! 🌟
Example 2: Fruit Counting
There are 128 apples in one basket and 93 in another. About how many apples are there total?
Let's estimate:
Round 128 to 130 (because 128 is closer to 130 than to 120)
Round 93 to 90 (because 93 is closer to 90 than to 100)
Now add: 130 + 90 = about 220 apples
The exact answer is 128 + 93 = 221. Our estimate of 220 was almost perfect! 🎉
Parent Tips 🌟
- Make it real: Practice estimating grocery totals or travel distances to show how useful this skill is in everyday life.
- Estimation games: Play "guess how many" with jars of small items (pennies, beans) to develop number sense.
- Celebrate close answers: Emphasize that estimates don't need to be perfect - being reasonably close is what matters!