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# Adding within 20 using place value blocks

Sal adds 8 + 6 using place value blocks. Created by Sal Khan.

## Want to join the conversation?

• Can I add within 40?
• yup any number
• what is 177+345
• 522, you could also write it as 500 + 20 + 2, or in word form, five hundred and twenty-two.
• Whats 1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000×55566778900099998771122345667889000987665443221+12234567890877665443×0
• The answer is not 0 because of order of operations. The answer is actually 55,566,778,900,099,998,771,122,345,667,889,000,987,665,443,221,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000.
• what's 100,0000000000+100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
• 2000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000? uh
• Hi khan
• 10+40+n=100
10+40+50
n+50=100
n=100
• You are wrong, MayaD. N is actually equal to 50. We do inverse operations. 100-50=50 It's actually easy
• What if you don't know your multiples?
• um just practice the multiplication table. 4 years ago, in 2nd grade, I wasn't good at multiplication. So I memorized it over the break. :) Hope this helps.
(1 vote)
• 10+90=100x10=1000-10-90=900
• 1999+8974