Making a whole dollar amount

In Primary 2, you wrote money in dollars and cents. Here are ten ten-cent coins. Ten times ten cents is one hundred cents. One hundred cents is one dollar. We will find the money needed to make a whole dollar amount. The minimart uncle has thirty-six dollars and twenty-five cents in his cash box. He wants one hundred dollars in the box. How much more money does he need? We must find this missing amount. So we subtract what he has from what he wants. Write what he wants on top. Write what he has below. Line up the decimal points. Hundreds, tens and dollars go on the left. Ten-cents and cents go on the right. Start with the cents. We cannot subtract five cents from zero cents. We need more cents. The next three places are zeros too. So we rename from the one hundred dollars. Rename one hundred dollars as ten tens. No hundreds are left. Write ten tens above this zero. This place is still zero. Rename ten dollars as ten groups of one dollar. Ten minus one is nine. Write ten dollars above this zero. This place is still zero. Rename one dollar as ten ten-cents. Ten minus one is nine. Write ten ten-cents above this zero. This place is still zero. Rename one ten-cent as ten cents. Ten minus one is nine. Write ten cents above this zero. Now subtract, from the right. Ten minus five is five. Nine minus two is seven. Nine minus six is three. Nine minus three is six. He needs sixty-three dollars and seventy-five cents more.

Aisyah has thirty-five cents. How much more money does she need to have one dollar? Try it first. Pause if you like. We cannot subtract five cents from zero cents. The next place is zero too. So we rename from the one dollar. Rename one dollar as ten ten-cents. No dollars are left. Write ten ten-cents above this zero. This place is still zero. Rename one ten-cent as ten cents. Ten minus one is nine. Write ten cents above this zero. Ten minus five is five. Nine minus three is six. Zero minus zero is zero. She needs sixty-five cents more.

Aisyah has two dollars and seventy-five cents. How much more money does she need to have ten dollars? Try it first. Pause if you like. We cannot subtract five cents from zero cents. The next two places are zeros too. So we rename from the ten dollars. Rename ten dollars as ten groups of one dollar. No tens are left. Write ten dollars above this zero. This place is still zero. Rename one dollar as ten ten-cents. Ten minus one is nine. Write ten ten-cents above this zero. This place is still zero. Rename one ten-cent as ten cents. Ten minus one is nine. Write ten cents above this zero. Ten minus five is five. Nine minus seven is two. Nine minus two is seven. She needs seven dollars and twenty-five cents more. Keep dollars and cents in their own places, and rename across the zeros.