Yellow
Green
Blue
Red
Magenta
Remove
Compact Method
Since Maruta makes the trades before she writes things down, each column never has more than one digit. That way she does not need the Base-Ten Recording Sheet to tell her the value of the digits—she just uses place value.
She explains it like this:
“8 ones plus 7 ones is 15 ones.
“I trade 15 ones for 1 ten and 5 ones.
“I write 5 in the answer space of the ones column.
“I write a little 1 in the tens column.”
“1 ten plus 7 tens plus 6 tens is 14 tens.
“I trade 14 tens for 1 hundred and 4 tens.
“I write 4 in the answer space of the tens column.
“I write a little 1 in the hundreds column.”
“Finally, I add the hundreds, 100 + 600 + 200. I get 9 hundreds.
“I put 9 in the answer space of the hundreds column.”
