Numbers to 100: 1st grade math in Mexico’s Sonoran Desert

Counting to 100, tens and ones, number names, comparing numbers, patterns, first to tenth and number bonds.

Walk among giant saguaro cactus, where roadrunners race and the desert meets a sea full of whales. Characters here greet you with “¡Hola!” (hello in Spanish), and eggs hatch into hybrids of animals like Gila woodpecker, elf owl, lesser long-nosed bat and Costa’s hummingbird.

What your child practices

Follows Number & Operations in Base Ten — Counting and Place Value (1.NBT.A–B).

• Counting to 100

  Count on and back to 100, and find which group has more.

  1.NBT.A.1

• Tens and ones

  See a number as tens and ones: buckets of 10, trays of 10, planks of 10.

  1.NBT.B.2

• Number names

  Read and write numbers to 100 in numerals and in words.

  1.NBT.A.1

• Comparing and ordering numbers

  Find the greater or smaller number by looking at the tens first.

  1.NBT.B.3

• Number patterns

  Count on and back by 2s, 5s and 10s to find what comes next.

  1.NBT.C.5

• First, second, third

  Use first to tenth and 1st, 2nd, 3rd to tell places in a line.

  1.NBT.A.1

• Number bonds to 10

  Find the missing part when two parts make a whole up to 10.

  1.OA.C.6

Try a problem from Mexico’s Sonoran Desert

Every problem is a short story set in the world. These are real problems from the game. Kids get endless new ones with different numbers.

Common mistakes, and how to help

Every wrong answer in Mixmonde is planned: it points to a named mistake, and the tip after a miss explains it with that problem’s numbers. These are the mistakes this world watches for, grouped the way the grown-ups’ dashboard shows them.

• Counting and sequences

  Losing track while counting: off by one, skipping or double-counting, or counting the wrong things (fence posts instead of gaps).

  Mistakes we catch: got lost at a new ten, skipped a number, counted the wrong way, counted by ones, skipped a step, counted from the wrong end, did not count the first one and counted the person too.

  Try at home: Count objects by touching or moving each one into a pile. Count on from a number other than 1 (“start at 8 and count 5 more”), and count back too.

• Reading the question

  The math works, but the answer is to a different question: a number already given, a halfway step, or only part of a two-step problem.

  Mistakes we catch: mixed up more and fewer, counted meters, not planks, gave the part that was given and gave the whole.

  Try at home: Read the question aloud together and ask “what are we trying to find?” before solving. Point at the question part of the sentence.

• Place value

  The digits are right but their places are not: a 3 in the tens is worth 30, not 3. This shows up when carrying, borrowing, lining up numbers or placing a decimal point.

  Mistakes we catch: counted tens as ones, swapped tens and ones, forgot the ones, swapped the digits, wrote each part as it sounds, mixed up teen and ty, compared the ones first and thought the same digits make the same number.

  Try at home: Make bundles of 10 with straws or pencils and a rubber band. Build numbers like 34 (3 bundles, 4 loose) and swap a bundle for 10 loose ones when you need to take some away.

• Order and direction

  The right idea done the wrong way round: taking the smaller digit from the bigger one, dividing backwards, swapping x and y, or flipping more and less.

  Mistakes we catch: mixed up greater and less and went the wrong way.

  Try at home: Use “more” and “fewer” in everyday talk: which plate has more grapes, how many fewer? Line things up side by side to compare.

• Choosing the operation

  The arithmetic is fine, but the wrong operation was picked: adding when the story takes away, or multiplying when it shares out.

  Mistakes we catch: added instead of taking away.

  Try at home: Act out word problems with toys: “3 birds, 2 fly away.” Ask “are we putting together or taking away?” before any numbers.

More Grade 1 worlds: Adding & Subtracting to 20 · Adding & Subtracting to 100 · Length, Time & Graphs · Shapes & Equal Shares · Equal Groups & Money