The worksheet "Addition Pyramids: Finding the Sum of Multi-Digit Numbers, Decimals, and Fractions" features pyramids where some of the blocks are filled in and some blocks are blank. The block above is the sum of the two blocks below, so students can use addition and subtraction to figure out the missing numbers.

For example, if the answer block contains the number 46 and one block below contains the number 11, students can either count up from 11 to 46 or subtract 11 from 46. Sometimes the missing number is an addend, sometimes it's the answer, and sometimes the answer turns into an addend for a different problem.

The first couple of pyramids on each worksheet are simple with single- and double-digit addition. Later problems tackle higher numbers as well as decimals and fractions, some of which include uncommon denominators. Some pyramids are small, with only three or four rows of numbers, while the largest pyramids have six or seven rows to give students a greater challenge.

Addition practice is important to developing mental math skills and fluency, but doing the same kind of math problem over and over again can get boring. You can keep your students engaged by having them complete addition problems in new and interesting ways. That could include new methods, like the box method, where students use a series of boxes with rows and columns to find an answer, but it can also involve the use of puzzles or brain teasers.

For example, students could be asked to fill in the boxes of a pyramid where the two boxes below are the addends for the box above. Students could finish a series of running addition problems or use a picture key to fill in the numbers in an addition problem before finding the answer. These types of addition brain teasers can be used with single- and multi-digit numbers, but they can also be used with fractions and decimals.