More than nine in a place

In the last lesson, we wrote one digit for each place on a place-value chart. Here are ten discs of ten. Ten tens make one hundred. Today, we rename ten discs in one place as one disc in the next place. Mei shows 4 thousands, 5 hundreds and twelve tens with number discs. What number does she show? First, we write what Mei shows. Look at the tens. There are twelve discs, but a place can show only one digit. Ten tens make 1 hundred. So we rename ten tens as 1 hundred. 5 hundreds and 1 more hundred make 6 hundreds, and 2 tens are left. So we write 4 thousands 6 hundreds 2 tens. There are no ones, so the ones digit is 0. Now each place has one digit, so write the digits together. Mei shows four thousand, six hundred and twenty.

Write 3 thousands 4 hundreds 6 tens fifteen ones as a numeral. Try it first. Pause if you like. Write what is given, place by place. The ones have fifteen discs, too many for one digit. Ten ones make 1 ten, so we rename ten ones as 1 ten. 6 tens and 1 more ten make 7 tens, and 5 ones are left. So we write 3 thousands 4 hundreds 7 tens 5 ones. Write the digits together. The numeral is three thousand, four hundred and seventy-five.

Write 6 thousands thirteen hundreds 2 tens 8 ones as a numeral. Try it first. Pause if you like. Write what is given, place by place. The hundreds have thirteen discs, too many for one digit. Ten hundreds make 1 thousand, so we rename ten hundreds as 1 thousand. 6 thousands and 1 more thousand make 7 thousands, and 3 hundreds are left. So we write 7 thousands 3 hundreds 2 tens 8 ones. Write the digits together. The numeral is seven thousand, three hundred and twenty-eight. When a place has ten or more discs, rename ten of them as one disc of the next place.