MENTAL MATH ADDITION FOR GRADE 5 - worksheetspack - Free Printable

Problem: Mental Addition Worksheet

The task is to solve the addition problems mentally. Here are the steps and solutions for each problem:

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#### (a) \( 430 + 270 \)
- Step 1: Add the hundreds place: \( 400 + 200 = 600 \)
- Step 2: Add the tens place: \( 30 + 70 = 100 \)
- Step 3: Combine the results: \( 600 + 100 = 700 \)

Answer: \( 700 \)

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#### (b) \( 580 + 320 \)
- Step 1: Add the hundreds place: \( 500 + 300 = 800 \)
- Step 2: Add the tens place: \( 80 + 20 = 100 \)
- Step 3: Combine the results: \( 800 + 100 = 900 \)

Answer: \( 900 \)

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#### (c) \( 210 + 690 \)
- Step 1: Add the hundreds place: \( 200 + 600 = 800 \)
- Step 2: Add the tens place: \( 10 + 90 = 100 \)
- Step 3: Combine the results: \( 800 + 100 = 900 \)

Answer: \( 900 \)

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#### (d) \( 105 + 435 \)
- Step 1: Add the hundreds place: \( 100 + 400 = 500 \)
- Step 2: Add the tens place: \( 0 + 30 = 30 \)
- Step 3: Add the ones place: \( 5 + 5 = 10 \)
- Step 4: Combine the results: \( 500 + 30 + 10 = 540 \)

Answer: \( 540 \)

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#### (e) \( 2020 + 3480 \)
- Step 1: Add the thousands place: \( 2000 + 3000 = 5000 \)
- Step 2: Add the hundreds place: \( 20 + 400 = 420 \)
- Step 3: Add the tens place: \( 0 + 80 = 80 \)
- Step 4: Add the ones place: \( 0 + 0 = 0 \)
- Step 5: Combine the results: \( 5000 + 420 + 80 + 0 = 5500 \)

Answer: \( 5500 \)

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#### (f) \( 3100 + 3400 \)
- Step 1: Add the thousands place: \( 3000 + 3000 = 6000 \)
- Step 2: Add the hundreds place: \( 100 + 400 = 500 \)
- Step 3: Combine the results: \( 6000 + 500 = 6500 \)

Answer: \( 6500 \)

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#### (g) \( 505 + 220 \)
- Step 1: Add the hundreds place: \( 500 + 200 = 700 \)
- Step 2: Add the tens place: \( 0 + 20 = 20 \)
- Step 3: Add the ones place: \( 5 + 0 = 5 \)
- Step 4: Combine the results: \( 700 + 20 + 5 = 725 \)

Answer: \( 725 \)

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#### (h) \( 332 + 520 \)
- Step 1: Add the hundreds place: \( 300 + 500 = 800 \)
- Step 2: Add the tens place: \( 30 + 20 = 50 \)
- Step 3: Add the ones place: \( 2 + 0 = 2 \)
- Step 4: Combine the results: \( 800 + 50 + 2 = 852 \)

Answer: \( 852 \)

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#### (i) \( 645 + 260 \)
- Step 1: Add the hundreds place: \( 600 + 200 = 800 \)
- Step 2: Add the tens place: \( 40 + 60 = 100 \)
- Step 3: Add the ones place: \( 5 + 0 = 5 \)
- Step 4: Combine the results: \( 800 + 100 + 5 = 905 \)

Answer: \( 905 \)

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#### (j) \( 270 + 305 \)
- Step 1: Add the hundreds place: \( 200 + 300 = 500 \)
- Step 2: Add the tens place: \( 70 + 0 = 70 \)
- Step 3: Add the ones place: \( 0 + 5 = 5 \)
- Step 4: Combine the results: \( 500 + 70 + 5 = 575 \)

Answer: \( 575 \)

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#### (k) \( 5150 + 2050 \)
- Step 1: Add the thousands place: \( 5000 + 2000 = 7000 \)
- Step 2: Add the hundreds place: \( 100 + 50 = 150 \)
- Step 3: Add the tens place: \( 50 + 0 = 50 \)
- Step 4: Add the ones place: \( 0 + 0 = 0 \)
- Step 5: Combine the results: \( 7000 + 150 + 50 + 0 = 7200 \)

Answer: \( 7200 \)

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#### (l) \( 4430 + 2470 \)
- Step 1: Add the thousands place: \( 4000 + 2000 = 6000 \)
- Step 2: Add the hundreds place: \( 400 + 400 = 800 \)
- Step 3: Add the tens place: \( 30 + 70 = 100 \)
- Step 4: Add the ones place: \( 0 + 0 = 0 \)
- Step 5: Combine the results: \( 6000 + 800 + 100 + 0 = 6900 \)

Answer: \( 6900 \)

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Final Answers:

\[
\boxed{
\begin{array}{ll}
(a) & 700 \\
(b) & 900 \\
(c) & 900 \\
(d) & 540 \\
(e) & 5500 \\
(f) & 6500 \\
(g) & 725 \\
(h) & 852 \\
(i) & 905 \\
(j) & 575 \\
(k) & 7200 \\
(l) & 6900 \\
\end{array}
}
\]