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USE MENTAL MATH TO ADD OR SUBSTRACT: USING COMPATIBLE NUMBERS
1. 80+79+20
2. 308+95+5
3. 480+255+20
4.365+289
5. 523-198
6. 537+180
7. 325+239+75
8. 87+38+62
9. 4500-280

We'll be glad to check them for you.

1. 80+79+20=100+20+59=120+59=179
2. 308+95+5=300+100+8=400+8=408
3. 480+255+20=480+20+255=500+255=755
4. 523-198=500-200=300 AND 23+2=25 THUS 300+25=325

The first three are right.

You didn't do # 4.

Number 5 is correct.

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USE MENTAL MATH TO ADD OR SUBSTRACT: 1. 80+79+20 2. 308+95+5 3. 480+255+20 4.365+289 5. 523-198 6. 537+180 7. 325+239+75 8. 87+38+62 9. 4500-280

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