Hundreds Chart Generator

How to make it

1. Choose where it startsStart at 1 for the classic 1 to 100 chart, at 0 for 0 to 99, or at 101 or 201 to keep counting past one hundred.
2. Hide some numbersLeave the slider at 0 for a complete chart, or hide up to 80 percent; the squares to empty are chosen at random.
3. Print chart and keyThe chart fills one page and the answer chart follows on the next, with every missing number printed in pink.

Four charts, from 0 up to 300

The chart is a ten by ten grid of squares that fills the width of the page, with the numbers in bold. Start at 1 and it runs from 1 to 100, the version found on most classroom walls. Start at 0 for 0 to 99, which some teachers prefer because every number in a row shares its tens digit. Start at 101 or 201 for charts that continue the count to 200 or 300.

The last column is lightly shaded, so the decade numbers 10, 20, 30 on a 1 to 100 chart, or 9, 19, 29 on a 0 to 99 chart, stand out as landmarks. When any numbers are hidden, a line under the title reads Fill in the missing numbers, and the title itself can be changed to anything you like, such as Hundred Square for a UK class.

Patterns a complete chart shows

Keep a complete chart in front of children for a while before asking them to fill one in. Moving one square to the right adds one. Moving one square down adds ten, so 34 sits directly above 44. Moving diagonally down and right adds eleven. Children who see these moves can add and subtract tens without counting by ones, which is the start of mental math with two-digit numbers.

Coloring is the classic activity. Shade the multiples of 2 with one pencil and children see alternate columns appear; the multiples of 5 make two columns; the multiples of 10 make the last column. The multiples of 3 and of 9 form diagonal stripes. This turns skip counting into a picture, and it links directly to the rows of a multiplication chart.

A favorite whole-class game uses the full chart: one child thinks of a number and the others ask questions such as is it more than 50, is it in the 7s column, until they find it. The questions themselves are place value practice.

Another quick routine: cover one square with a sticky note or a counter and ask what is hidden, then what is one more, ten more, one less and ten less. Children answer by looking at the neighbors rather than counting from the start. Done for two or three minutes a day, it builds the habit of moving around the chart by tens and ones, which is what the missing-number sheets then test on paper.

Filling in a chart with missing numbers

When some squares are blank, children can find each missing number in two ways: by counting along the row from the number to its left, or by using the column, where the number above is ten less and the number below ten more. Good fillers use both, checking one against the other. If a child counts from 1 every time, model the column trick on a few squares and ask them to try it on the next row.

The share hidden changes the task. At 10 to 20 percent, nearly every gap has both neighbors, so it is a gentle check of number order. At 30 percent, the starting setting, some gaps sit beside each other. At 60 to 80 percent, the chart is close to blank and children rebuild it from a few clues, which is real practice in writing numbers to 100. A New variant hides a different set of squares with the same settings.

Hundreds charts by grade

On US and Canadian sheets (those that open on Letter), charts show CCSS 1.NBT.A.1 in the footer, the first-grade standard for counting to 120 and reading and writing numerals in that range. The same code prints on the 101 to 200 and 201 to 300 charts, although the standard itself stops at 120. Kindergarten classes use complete 1 to 100 charts for counting by ones and tens and for finding numbers; first graders fill in charts with missing numbers, and the 101 to 200 chart carries them past 120. Second graders use 101 to 200 and 201 to 300 when counting within 1,000, especially across tricky changes like 199 to 200.

In England, where the chart is usually called a hundred square, Year 1 children count to and across 100, and Year 2 children use the square for counting in tens from any number. In Australia, children typically count to 120 by Year 1 and use charts for skip counting in Year 2. For children still learning to form digits, a few pages of number tracing to 100 help before writing a whole chart.

Should the chart start at 0 or 1?

Teachers disagree, and both have good reasons. The 1 to 100 chart matches how children count, ending each row at a decade: 1 to 10, 11 to 20. The 0 to 99 chart keeps the tens digit the same along each row, so the row of the 40s really holds 40 to 49, which helps place value. Some schools use one in the early grades and switch later.

Whichever you choose, use the same one for a while; changing charts each week confuses children who are building a mental picture of where numbers sit. The 101 to 200 and 201 to 300 charts behave exactly like the 1 to 100 chart with a hundreds digit added, which is a useful point to make when introducing three-digit numbers on place value worksheets or on number line worksheets counting by 10s.

Common slips, checking, and how much to hide

Typical errors: reversing digits so 41 appears where 14 belongs, losing track at the end of a row and repeating or skipping a number, writing 100 as 1000 or 10, and on the 101 to 200 chart dropping the hundreds digit. The answer chart prints every number, with the ones that were hidden in pink, so you only need to check the pink squares against the child's page.

For a quick daily task, hide 10 percent and ask for the missing numbers in a few minutes. For practice, 30 to 50 percent. For a check of counting to 100, 70 to 80 percent. Print a different variant for each child on a table so the gaps differ, and keep the matching answer charts together by the sheet number in the footer.

Common Core State Standards: © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.