172+553
Solution: Align the two addend units, and then add the numbers in the same counting unit respectively. When the addition result exceeds 10, it will reach the high position of 1, and the addition of the high position needs to accumulate the low position result of 1.
Problem solving process:
Step 1: 2+3=5
Step 2: 7+5=2 to the high position, 1.
Step 3: 1+5+ 1=7.
According to the above calculation steps, the comprehensive calculation result is 725.
Checking calculation: 725-553= 172
Extended data ~ check result: align the units of the subtrahend and the minuend, and then subtract them from the corresponding counting units. If the subtraction is not enough, you need to borrow 1 from the high position and calculate the results in turn. If the subtrahend is less than the minuend, add a negative sign to the final result of two numbers. Fractional subtraction can refer to the integer subtraction step;
Problem solving process:
Step 1: 5-3=2
Step 2: 12-5=7 high borrowing 1.
Step 3: 7-5- 1= 1
According to the above calculation steps, the comprehensive calculation result is 172.
If in doubt, please ask questions. If satisfied, please adopt them.