PencilGoGrade 3 · Math · Addition
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Grade 3 Math Worksheet
Find the sum.
300 + 200 = ____
600 + 386 = ____
190 + 60 = ____
600 + 200 = ____
100 + 197 = ____
626 + 50 = ____
100 + 200 = ____
400 + 246 = ____
119 + 90 = ____
500 + 300 = ____
400 + 365 = ____
759 + 20 = ____
500 + 100 = ____
100 + 138 = ____
240 + 20 = ____
400 + 100 = ____
400 + 376 = ____
251 + 70 = ____
Adding a whole ten or a whole hundred is the quickest kind of mental addition: only one digit of the other number changes, and sometimes a second one when the sum crosses into the next hundred. On this worksheet your child adds a whole number of tens or hundreds to another number and writes the sum, with no column to set up. Building Confidence adds whole tens to a two-digit number, On Level adds whole hundreds and whole tens to three-digit numbers, and Challenge Me uses sums that carry into the next hundred, such as 870 + 60.
Every sum stays within 1,000. Encourage your child to add the tens or hundreds first and to say the answer aloud, as in 356 + 40: three hundred fifty-six, forty more, three hundred ninety-six.
Common Core standard: 3.NBT.A.2
356 + 40: add the tens, 50 + 40 = 90, so the sum is 396.
Adding the whole ten to the ones digit, so 356 + 40 becomes 396 only by luck and 78 + 30 becomes 108 by mistake.
Add only the tens (or hundreds) first, then put the rest of the number back.
Adding the whole ten to the ones digit, so 356 + 40 becomes 396 only by luck and 78 + 30 becomes 108 by mistake.
Add only the tens (or hundreds) first, then put the rest of the number back.
Yes. All 6 printable versions on this page are free to download and print, with no account needed.
Similar: Addition Within 1,000
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