Addition of up to two 6-digit numbers with double regrouping

Group Activity 3

In groups:

Task: Add 417 253 to 26 395

Example 3

1. Write the two numbers in the place value chart as shown:

1. To add the two numbers:
   ​Add the digits in each place value starting from the ones.
   ​What do you notice in the addition of the digits in the tens and thousands place values?
2. Discuss and share your results with other groups.

a)

What is the sum of 473 209 and 218 534? Write the addition in a vertical form.

Steps

1. Add ones: 9 + 4 = 13.
2. Regroup 13 ones as 1 ten 3 ones.
   Write ​3 in the ones column and 1 above 0 in the tens column.
3. Add tens to get 1 + 0 + 3 = 4.
4. Add hundreds 2 + 5 = 7.
5. Add thousands to get 6 + 8 = 14 thousands.
6. Regroup 14 thousands into 1 ten thousands and 4 thousands. Write 4 in the thousands column and 1 above 7 in the tens of thusands column.
7. Add ten thousands to get 1 + 7 + 1 = 9.
8. Add hundred thousands 4 + 2 = 6.

Therefore, 476 209 + 218 534 = 694 743

b)

Steps

1. Add ones: 5 + 5 = 10.
2. Regroup the tens ones into 1 ten and 0 ones.
3. Write O in ones column and 1 ten above 0 in tens column.
4. Add tens to get 1 + 0 + 2 = 3 tens.
5. Add hundreds to get 1 + 8 = 9 hundreds.
6. Add thousands to get 6 + 9 = 15 thousands.
7. Regroup the 15 thousands into 1 tens of thousand and 5 thousand.
   ​Write 5 thousand in thousands column and 1 above 5 in tens of thousands column.
8. Add tens of thousands to get 1 + 5 + 3 = 9 tens of thousands.
9. Add hundreds of thousands to get 3 + 6 = 9 hundreds of thousands.

Therefore, Sh 356 105 + Sh 639 825 = Sh 995 930.